Proxy Statement (Form DEF 14A)

TO OUR SHAREHOLDERS:

We will hold the 2025 Annual Meeting of Shareholders of First US Bancshares, Inc. (the "Company") at 10:00 a.m., Central Time, on Thursday, May 1, 2025. This year we will be conducting the annual meeting online via live webcast in order to allow our shareholders and other attendees to participate from any location. Details regarding how to participate in the virtual annual meeting and the business to be conducted are more fully described in the accompanying notice of the annual meeting and proxy statement.

We have enclosed a notice of the meeting, a proxy statement, a proxy card and the Annual Report to Shareholders for 2024 and hope that you will study the enclosed materials carefully and participate in the virtual meeting.

Whether or not you plan to participate in the meeting, please complete, sign and date the enclosed proxy card and retuit as promptly as possible. You may retuthe proxy card by mail in the accompanying envelope, or you may vote your shares via the internet or by telephone. Please review the instructions on each of these options in the proxy statement and on your proxy card. You may revoke your proxy by voting during the meeting, by signing and delivering a later-dated proxy card, by giving written notice of revocation to the Secretary of the Company or by a later vote via the internet or by telephone at any time before the proxy is voted.

March 27, 2025

FIRST US BANCSHARES, INC.

3291 U.S. Highway 280

Birmingham, Alabama 35243

(205) 582-1200

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

TO THE SHAREHOLDERS OF FIRST US BANCSHARES, INC.:

First US Bancshares, Inc. (the "Company") will hold its 2025 Annual Meeting of Shareholders (the "Annual Meeting") in a virtual format via live webcast on Thursday, May 1, 2025, at 10:00 a.m., Central Time, for the following purposes:

The Board of Directors of the Company has fixed the close of business on March 12, 2025, as the record date for the determination of shareholders entitled to notice of and to vote at the Annual Meeting. A complete list of the shareholders of the Company will be available and open for examination by any shareholder of the Company during ordinary business hours beginning April 21, 2025.

All shareholders are cordially invited to participate in the virtual Annual Meeting. You will be able to attend the Annual Meeting online and submit your questions during the meeting by visiting https://meetnow.global/MZ6SKCF. In order to participate, you will need the control number included on your Notice of Internet Availability of Proxy Materials or proxy card if you request a hard copy of the proxy materials. Information about the Annual Meeting, including further instructions on how to participate in the Annual Meeting, can be found at the following website: www.edocumentview.com/FUSB.

Whether or not you plan to participate during the Annual Meeting, you are requested to complete, sign and date the enclosed proxy card and send it promptly by mail in the envelope provided for this purpose, or vote your shares via the internet or by telephone using the instructions provided in the proxy statement and on your proxy card. The proxy may be revoked by voting during the Annual Meeting, by signing and delivering a later-dated proxy card, by giving written notice of revocation to the Secretary of the Company or by a later vote via the internet or by telephone at any time prior to the voting thereof.

By Order of the Board of Directors,

Beverly J. Dozier

Corporate Secretary

Birmingham, Alabama

March 27, 2025

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE VIRTUAL ANNUAL MEETING OF SHAREHOLDERS TO BE HELD ON MAY 1, 2025: THE COMPANY'S PROXY STATEMENT AND 2024 ANNUAL REPORT ARE AVAILABLE AT www.edocumentview.com/FUSB.

PROXY STATEMENT

TABLE OF CONTENTS

FIRST US BANCSHARES, INC.

3291 U.S. Highway 280

Birmingham, Alabama 35243

(205) 582-1200

PROXY STATEMENT

FOR THE

2025 ANNUAL MEETING OF SHAREHOLDERS

TO BE HELD ON MAY 1, 2025

INTRODUCTION

This Proxy Statement is furnished on or about March 27, 2025, by First US Bancshares, Inc. (the "Company") to the holders of common stock of the Company in connection with the 2025 Annual Meeting of Shareholders, and any adjournments or postponements thereof, to be held on Thursday, May 1, 2025, at 10:00 a.m., Central Time, in a virtual format via live webcast (the "Annual Meeting"). The matters to be considered and acted upon are:

The Board of Directors of the Company (the "Board") is soliciting the proxy, which is revocable at any time before it is voted. You may revoke the proxy by voting during the virtual Annual Meeting, by signing and delivering a later-dated proxy card, by giving written notice of revocation to the Secretary of the Company or by a later vote via the internet or by telephone. We must, however, actually receive the written notice, later-dated proxy card or later internet or telephone vote before the vote of the shareholders during the Annual Meeting. We will vote all properly executed proxies delivered pursuant to this solicitation during the Annual Meeting and in accordance with instructions given, if any. If no instructions are given, we will vote the proxies as recommended by the Board - FOR all of the nominees listed in Proposal 1 and FOR Proposals 2 and 3 - and in accordance with the instructions of management as to any other matters that may come before the Annual Meeting.

To vote by proxy, you must do one of the following:

NOTE: If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the beneficial owner of shares held in "street name," and these proxy materials are being forwarded to you by your broker, bank or other nominee who is considered the shareholder of record with respect to those shares. You must follow the instructions for voting your shares that you receive from your broker, bank or other nominee. Please refer to the section entitled "Voting Shares Held in 'Street Name'" for more information about how to vote your shares.

1

The Company will pay the cost of soliciting proxies. In addition to soliciting proxies by mail, we may solicit proxies by personal interview, telephone, facsimile and electronic communication. Banks, brokers or other nominees will forward the proxy materials to their principals or beneficial owners and obtain authorization for the execution of proxies. The Company will, upon request, reimburse banks, brokers and other nominees for their reasonable expenses in forwarding proxy materials to their principals or beneficial owners.

Shareholders Eligible to Vote

We are sending this Proxy Statement to shareholders of record as of the close of business on March 12, 2025. Only shareholders as of this date are eligible to vote during the Annual Meeting. At the close of business on March 12, 2025, there were 5,752,262 shares of common stock of the Company, par value $0.01 per share, outstanding and eligible to receive notice of and to vote at the Annual Meeting. Each shareholder is entitled to one vote in person or by proxy for each share of common stock held on all matters properly to come before the Annual Meeting.

How to Participate in the Annual Meeting

You will be able to attend the Annual Meeting online and submit your questions during the meeting by visiting https://meetnow.global/MZ6SKCF. You also will be able to vote your shares online by attending the Annual Meeting by webcast. In order to participate, you will need the control number included on your Notice of Internet Availability of Proxy Materials or proxy card if you request a hard copy of the proxy materials. If you are a registered shareholder (i.e., you hold your shares through our transfer agent, Computershare), you do not need to register to attend the Annual Meeting virtually on the internet.

If you hold your shares through an intermediary, such as a bank or broker, and do not have a control number, you must register in advance by following the instructions outlined below. To register to attend the Annual Meeting online, you must submit proof of your proxy power (legal proxy) reflecting your First US Bancshares, Inc. holdings along with your name and email address to Computershare. Requests for registration must be labeled as "Legal Proxy" and be received no later than 4:00 p.m. (Central Time), on April 28, 2025. You will receive a confirmation of your registration by email after Computershare receives your registration materials.

Requests for registration should be directed to Computershare at the following:

Information About a Quorum

At the Annual Meeting, the presence of a majority of the outstanding shares of the Company's common stock entitled to vote, represented in person or by proxy, shall constitute a quorum for the transaction of business. If a quorum is not present, or if the Chairperson of the Annual Meeting decides that more time is necessary for the solicitation of proxies, then the Chairperson may adjouthe Annual Meeting, with or without a shareholder vote. Alternatively, if there is a shareholder vote to adjouthe Annual Meeting based on the absence of a quorum, the named proxies will vote all shares of common stock for which they have voting authority in favor of the adjournment.

Vote Required to Approve Proposals

Assuming the presence of a quorum, the directors of the Company will be elected by a plurality of the shares represented at the Annual Meeting and entitled to vote in the election of directors - in other words, the

2

director nominees receiving the most votes will be elected (Proposal 1). The ratification of the appointment of Carr, Riggs & Ingram, LLC as independent registered public accountants for the year ending December 31, 2025 (Proposal 2) will require the affirmative vote of a majority of the shares represented at the Annual Meeting in person or by proxy and entitled to vote on the matter. Proposal 3 calls for the advisory (non-binding) approvalof the Company's executive compensation and will require for adoption the affirmative vote of a majority of the shares represented at the Annual Meeting in person or by proxy and entitled to vote on the matter.

Following the Annual Meeting, we will file a Current Report on Form 8-K withthe Securities and Exchange Commission (the "SEC") to disclose the results of voting on each proposal, as required by applicable rules.

Abstentions

A shareholder may abstain from voting or withhold his or her vote, as applicable (collectively, "abstentions"), with respect to each item submitted for shareholder approval, including the election of directors. Abstentions will be counted as present for purposes of determining the existence of a quorum but will be counted as not voting on any proposal brought before the Annual Meeting. Based on the plurality voting standard, abstentions will have no effect on the election of directors (Proposal 1). An abstention as to the ratification of the appointment of Carr, Riggs & Ingram, LLC as independent registered public accountants for the year ending December 31, 2025 (Proposal 2) and the advisory approval of the Company's executive compensation (Proposal 3) will have the same effect as voting against these proposals, given that the outcome of each proposal is determined by the shares represented at the Annual Meeting and entitled to vote on the matter.

Voting Shares Held in "Street Name"

If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the beneficial owner of shares held in "street name," and these proxy materials are being forwarded to you by your broker, bank or other nominee who is considered the shareholder of record with respect to those shares. As the beneficial owner, you have the right to direct your broker, bank or other nominee on how to vote, and you are also invited to participate in the virtual Annual Meeting. Your broker, bank or other nominee has enclosed a voting instruction card for you to use in directing the broker, bank or other nominee regarding how to vote your shares. If you hold your shares in "street name," it is critical that you retuthe voting instruction card as directed by your broker, bank or other nominee if you want your votes to count in the election of directors (Proposal 1) and with respect to the non-binding advisoryvote regarding the Company's executive compensation (Proposal 3).

Under applicable law, if you hold your shares in "street name" and do not indicate to your broker, bank or other nominee how you want your shares to be voted in the election of directors (Proposal 1) or the executive compensation matter (Proposal 3), then your broker, bank or other nominee may not vote on these matters. Therefore, if you hold your shares in "street name" and do not instruct your bank, broker or other nominee on how to vote in the election of directors or with respect to the executive compensation matter, your shares will not be voted with respect to such matters or on any other proposal with respect to which your broker, bank or other nominee does not have discretionary authority (resulting in a "brokernon-vote").

Broker non-votes arecounted for general quorum purposes but are not taken into account when determining voting outcomes with respect to any matter for which a broker does not have discretionary authority to vote. Broker non-votes willnot be counted for purposes of the election of directors (Proposal 1) and will have no effect on the outcome of such proposal. Broker non-votes willnot be taken into account in determining the outcome of the non-binding advisoryvote regarding executive compensation (Proposal 3). Your bank, broker or other nominee will continue to have discretion to vote any uninstructed shares on the ratification of the appointment of Carr, Riggs & Ingram, LLC as our independent registered public accountants for the year ending December 31, 2025 (Proposal 2); therefore, there should be no broker non-votes withrespect to this item.

3

PROPOSAL 1

ELECTION OF DIRECTORS

The Company's Bylaws provide that the Board shall consist of not less than three and not more than 25 directors, and, if a number is not fixed by the Board, the Bylaws state that there shall be 16 directors. There are currently 11 directors serving on the Board. All current members of our Board will stand for reelection at the Annual Meeting. The Nominating and Corporate Governance Committee and the Board have both determined that a Board consisting of 11 persons is practical and efficient at this point in time.

Based on the nominations of the Nominating and Corporate Governance Committee, the Board recommends that the shareholders elect the 11 director nominees named below to hold office until the 2026 Annual Meeting of Shareholders of the Company and until their successors are elected and qualified. Unless "Withhold" is noted as to all or some of the nominees, proxies will be voted at the Annual Meeting FOR the election of the 11 nominees to the Board. Shareholders may not vote for a greater number of persons than the number of nominees named.THEBOARD RECOMMENDS THAT YOU VOTEFORTHE ELECTION OF THE 11 NOMINEES.

While we know of no reason why any nominee would be unable to serve as a director, if, before the voting during the Annual Meeting, any person nominated to be elected as a director is unable to serve, then the shares that would otherwise be voted for that person may be voted for the election of a substitute person recommended by the Board.

The following provides certain biographical information about the individuals who have been nominated for election as directors of the Company. The biographical information for each of the nominees below contains a description of the individual's service as a director; business experience; director positions held currently or at any time during the last five years, if applicable, with a company registered pursuant to Section 12 or Section 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or an investment company; information regarding involvement in certain legal or administrative proceedings, if applicable; and the experiences, qualifications, attributes and skills that caused the Board to determine that the individual should serve as a director. The stock ownership with respect to each nominee is set forth in the table entitled "Security Ownership of Certain Beneficial Owners and Management" that appears in this Proxy Statement.

Following the Annual Meeting, the Company, as the sole shareholder of First US Bank (the "Bank"), intends to reelect all of the newly-elected directors of the Company as directors of the Bank. Information regarding the executive officers of the Company who are not directors is also provided below.

4

Information About Director Nominees

5

6

7

Information About Executive Officers Who Are Not Also Directors

8

None of the directors or executive officers are related to any other director or executive officer of the Company.

9

CORPORATE GOVERNANCE

The Company is committed to having sound corporate governance principles. Operating in accordance with such principles is essential to running the Company's business effectively and to maintaining the Company's integrity in the marketplace. The Company's Board has adopted a Code of Business Conduct and Ethics that sets forth basic principles to guide the Company's and the Bank's employees, including the Chief Executive Officer, the Chief Financial Officer and other senior executive officers, in their conduct and compliance with applicable laws and governance principles. A copy of the Code of Business Conduct and Ethics is available on our website at https://www.fusb.com under the tabs "Investors - Governance - FUSB Policies." We will furnish any person without charge, upon written request, a copy of the Code of Business Conduct and Ethics. In the event the Company amends or waives any of the provisions of the Code of Business Conduct and Ethics applicable to our Chief Executive Officer, the Chief Financial Officer and other senior executive officers that relate to any element of the definition of "code of ethics" enumerated in Item 406(b) of Regulation S-Kunder the Exchange Act, the Company intends to disclose these actions on the Company's website.

The following is a summary of the Company's director independence standards, the Board and committee structure, the director nomination process and the procedures for shareholders to follow to communicate with the Board.

Director Independence

The Nasdaq Stock Market, LLC, the exchange on which the Company's common stock is listed ("Nasdaq"), requires that a majority of the Company's Board members be "independent." Accordingly, because the Board currently has 11 members, at least six of the directors must be independent. In accordance with Nasdaq's listing rules, a director is not considered to be independent unless the Board determines that the director has no relationship with the Company or its subsidiaries (either directly or as a partner, shareholder or officer of an organization that has a relationship with the Company or any of its subsidiaries) that would interfere with the exercise of the director's independent judgment in carrying out the responsibilities of a director. Members of the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee also must meet the applicable independence tests in the Nasdaq listing rules and the federal securities laws.

The Board has determined that none of the directors standing for reelection, with the exception of Mr. House, has any material relationship with the Company or any of its subsidiaries (either directly or as a partner, shareholder or officer of an organization that has a relationship with the Company or any of its subsidiaries) that would interfere with the exercise of independent judgment in carrying out his or her responsibilities. In making this determination, the Board considered transactions and relationships between each director or his or her immediate family and the Company, its subsidiaries and their employees. The purpose of this review was to determine whether any such transactions or relationships were material and possibly inconsistent with a determination that the director was independent. Mr. House is not independent because of his employment as the President and Chief Executive Officer of the Company and the Bank.

While conducting its review of director independence, the Board specifically considered the various deposit, loan and other relationships that each director has with the Bank, including the transactions disclosed under "Transactions with Related Persons," but determined in each case that these relationships did not interfere with their exercise of independent judgment in carrying out their responsibilities as directors. Additionally, the Board considered that the Company has leased various properties from entities with which Mr. Thompson is affiliated since the Bank acquired The Peoples Bank in 2018. The Company's lease arrangements with these entities are negotiated on the same basis and subject to the same terms and conditions as the Company's other similar lease arrangements. The Board determined that the amounts paid by the Company to Mr. Thompson's entities during each of the last three fiscal years were not material to the Company or Mr. Thompson. Based on this review, the Board concluded that the Company's relationship with Mr. Thompson's entities does not interfere with Mr. Thompson's exercise of independent judgment in carrying out his responsibilities as a director.

10

Company Leadership Structure

The business of the Company is managed under the direction of the Board, which is elected by our shareholders. The basic responsibility of the Board is to lead the Company by exercising its business judgment to act in what each director reasonably believes to be the best interests of the Company and its shareholders. Leadership is important to the effective operation of the Board for the benefit of the Company. The role of the Chairperson includes providing continuous feedback on the direction, performance and strategy of the Company, presiding over meetings of the Board, setting the Board's agenda with management and the Lead Independent Director, and leading the Board in anticipating and responding to risks faced by the Company.

The roles of Chief Executive Officer and Chairperson of the Board were separate until January 2025, when the Board, at the recommendation of the Nominating and Corporate Governance Committee, elected Mr. House, the President and Chief Executive Officer of the Company and the Bank, as Chairperson of the Board. Previously, he had served as Vice Chairperson of the Board since November 2022. Also in January 2025, the Nominating and Corporate Governance Committee recommended, and the Board approved, designating Mr. Briggs as the Vice Chairperson of the Board and the Lead Independent Director in accordance with the Company's Lead Director Charter. The Board believes that this leadership structure will enhance communication and cooperation among the directors and members of management. The Board may reconsider this leadership structure from time to time based on then-current considerations.

Risk Oversight

The Company is exposed to a number of risks and regularly undertakes a review to identify and evaluate these risks and develop plans to manage them effectively. While the Chief Executive Officer has overall responsibility for risk assessment, management and prioritization, the Board has an active role in the risk oversight process.

The Board regularly reviews information regarding the Company's financial, credit, liquidity, operational, legal, regulatory, compliance, reputational and strategic risks based on reports from management, including the Chief Executive Officer and the Chief Financial Officer. The Audit Committee is primarily responsible for overseeing the Company's enterprise risk management ("ERM") program, including the process by which management assesses, prioritizes and manages the Company's material risks, and receives periodic reports from the Chief Risk Officer on the status of the ERM program. Certain other committees of the Board are responsible for specific oversight of the risk oversight process when a particular risk falls within the purview of that particular committee. The Audit Committee reviews the Company's financial risks (including risks required to be monitored under the Sarbanes-Oxley Act) and risks relating to financial reporting, audit matters and internal controls. The Nominating and Corporate Governance Committee specifically oversees risks associated with the independence of Board members, potential conflicts of interest and governance items. The Compensation Committee of the Board oversees the management of risks relating to the Company's compensation policies, plans, and practices, including executive compensation. The Retail, Operation and Compliance Committee of the Bank's Board of Directors oversees risk management policies with respect to retail products and operational functions, along with certain compliance and audit functions. The Information Technology Steering Committee oversees information technology services, cybersecurity and third-party technology risk exposure of the Bank. The Directors' Loan Committee oversees risks relative to certain loan and credit functions and approval processes of the Bank. The conclusions of each Board committee with respect to issues falling within the purview of that particular committee are brought to the attention of all Board members at the regularly-scheduled meetings of the Board. This enables the Board and its committees to coordinate with respect to the risk oversight function and responsibility.

Board Structure and Committees

The Board conducts its business through meetings of the Board and Board committees. Further, executive sessions of the independent directors of the Board are to be held at least two times a year and otherwise as

11

needed. These sessions are chaired by the Chairperson of the Board or another independent director selected by a majority of the independent directors.

During 2024, the Board met ten times in regularly scheduled meetings and held one special meeting. All of the incumbent directors attended at least 75% of the aggregate of the total number of meetings of the Board and the total number of meetings held by all committees of the Board on which he or she served during the year.

Directors are encouraged but not required to attend the Annual Meeting of Shareholders each year. Ten individuals then serving as the Company's directors attended the Company's 2024 Annual Meeting of Shareholders held on April 25, 2024, with one director not attending.

Audit Committee

The Audit Committee assists the Board with its oversight responsibilities with respect to the financial reports and other financial information provided by the Company to its shareholders and others, the Company's financial policies and procedures and disclosure controls and procedures, the Company's system of internal controls and the Company's auditing, accounting and financial reporting processes. The Audit Committee operates under a written charter, a copy of which is posted on the Company's website at https://www.fusb.com under the tabs "Investors - Governance - FUSB Policies." The Audit Committee is required on an annual basis to review and reassess the adequacy of its charter and recommend any changes to the full Board. The Audit Committee last reviewed and assessed the adequacy of its charter on March 12, 2025. The Audit Committee met 11 times during 2024. The Audit Committee Report appears later in this Proxy Statement.

Certain Nasdaq listing rules and the federal securities laws require that at least one member of the Audit Committee must have an understanding of generally accepted accounting principles and financial statements, the ability to assess the general application of such principles in connection with the accounting for estimates, accruals and reserves, experience preparing, auditing, analyzing or evaluating financial statements or experience actively supervising one or more persons engaged in such activities, an understanding of internal control over financial reporting and an understanding of audit committee functions. The Board has determined that currently Marlene M. McCain and Robert Stephen Briggs each has the requisite attributes of an "audit committee financial expert."

The current members of the Audit Committee are Marlene M. McCain, Chairperson, Robert Stephen Briggs, Robert C. Field, Jack W. Meigs, Staci M. Pierce, and Bruce N. Wilson. The Board has carefully evaluated the backgrounds of the members of the Audit Committee and determined that such members qualify as "independent," as defined in the applicable Nasdaq listing rules, and such members satisfy the heightened independence standards under SEC rules.

Compensation Committee

The Compensation Committee assists the Board in overseeing and determining executive compensation. Among other responsibilities, the Compensation Committee reviews, recommends and approves salaries and other compensation of the Company's executive officers and administers the Company's equity compensation plans that may be in place from time to time. The Chief Executive Officer assists the Compensation Committee with determining the amount of compensation to be paid to the other executive officers but does not play a role in the final determination or approval of his own compensation. The Compensation Committee operates under a written charter, a copy of which is posted on the Company's website at https://www.fusb.com under the tabs "Investors - Governance - FUSB Policies." The Compensation Committee is required on an annual basis to review and reassess the adequacy of its charter and recommend any changes to the full Board. The Compensation Committee last reviewed and assessed the adequacy of its charter on March 12, 2025. The Compensation Committee met four times during 2024. The Compensation Committee Report appears later in this Proxy Statement.

12

The Compensation Committee has reviewed the Company's compensation programs, plans and practices for all of its employees as they relate to risk management and risk-taking initiatives to ascertain if they serve to encourage or incentivize risks that are "reasonably likely to have a material adverse effect" on the Company. As a result of this process, the Compensation Committee concluded and informed the Board that, based on the Company's current compensation programs, plans and practices, there are no such risks.

The current members of the Compensation Committee are Bruce N. Wilson, Chairperson, J. Lee McPhearson, Jack W. Meigs, Aubrey S. Miller, and Staci M. Pierce. The Board has carefully evaluated the backgrounds of the members of the Compensation Committee and determined that such members qualify as "independent," as defined in the applicable Nasdaq listing rules and as defined in the committee's charter.

Nominating and Corporate Governance Committee

Among other responsibilities, the Nominating and Corporate Governance Committee reviews and recommends the selection of directors and members of committees of the Board and reviews and establishes the governance practices of the Company. The Nominating and Corporate Governance Committee operates under a written charter, a copy of which is posted on the Company's website at https://www.fusb.com under the tabs "Investors - Governance - FUSB Policies." The Nominating and Corporate Governance Committee is required on an annual basis to review and reassess the adequacy of its charter and recommend any changes to the full Board. The Nominating and Corporate Governance Committee last reviewed and assessed the adequacy of its charter on March 12, 2025. The Nominating and Corporate Governance Committee met eight times during 2024.

The members of the Nominating and Corporate Governance Committee are Jack W. Meigs, Chairperson, J. Lee McPhearson, Aubrey S. Miller, and Bruce N. Wilson. The Board has carefully evaluated the backgrounds of the members of the Nominating and Corporate Governance Committee and determined that such members qualify as "independent," as defined in the applicable Nasdaq listing rules, including the heightened independence standards applicable to members of compensation committees of listed companies.

Executive Committee

Among other responsibilities, the Executive Committee, created in November 2022, provides advice to the executive officers of the Company and takes actions on behalf of the Board between meetings of the Board. The Executive Committee is required on an annual basis to review and reassess the adequacy of its charter and recommend any changes to the full Board. The Executive Committee met four times during 2024.

The members of the Executive Committee are James F. House, Chairperson, Robert Stephen Briggs, Robert C. Field, David P. Hale, Marlene M. McCain, and Aubrey S. Miller.

Consideration of Director Nominees

Criteria and Board Composition

Criteria that are used by the Nominating and Corporate Governance Committee in connection with evaluating and selecting new directors include factors relating to whether the candidate would meet the definition of "independent," as defined by the applicable Nasdaq listing rules, as well as the candidate's skills, occupation and experience in the context of the needs of the Board. The Board believes that the backgrounds and qualifications of the directors, considered as a group, should provide a significant composite mix of experience, knowledge and abilities that will allow the Board to fulfill its responsibilities.

The Nominating and Corporate Governance Committee continually reviews the qualifications and responsibilities of all directors in consideration of the Board's overall responsibility to shareholders. The Nominating and Corporate Governance Committee also considers issues of relevant experience, intelligence, independence, commitment, integrity, diligence, conflicts of interest, age, compatibility with the Company's

13

other Board members and management team, understanding of the Company's business and culture, the ability to act in the best interests of the shareholders, and other factors deemed relevant. The goal of this process is to assemble a group of directors with deep, varied experience, sound judgment and commitment to the success of the Company. For a discussion of the individual experience and qualifications of our directors, refer to "Proposal 1 - Election of Directors" in this Proxy Statement.

Process for Identifying and Evaluating Director Nominees

The process followed by the Nominating and Corporate Governance Committee to identify and evaluate candidates includes requests to Board members and others for recommendations, meetings from time to time to evaluate biographical information and background material relating to potential candidates, and interviews of selected candidates by members of the Nominating and Corporate Governance Committee and the Board. Assuming that the appropriate biographical and background material discussed below is provided on behalf of candidates recommended by shareholders, the Nominating and Corporate Governance Committee will evaluate those candidates by applying substantially the same criteria and following substantially the same process as that used for candidates submitted by Board members. With respect to Messrs. Field and Thompson and Ms. Pierce, each of whom was elected to the Board following the 2024 Annual Meeting of Shareholders, such candidates were recommended to the Nominating and Corporate Governance Committee by other current members of the Board. 

Director Nominees Proposed by Shareholders

The Nominating and Corporate Governance Committee will consider candidates recommended by shareholders for inclusion by the Board in the slate of nominees that the Board recommends to the shareholders for election. In considering whether to recommend any candidate for inclusion in the Board's slate of recommended director nominees, including candidates recommended by shareholders, the Nominating and Corporate Governance Committee applies the selection criteria and follows the process described above.

Shareholders may recommend individuals for the Nominating and Corporate Governance Committee to consider as potential director candidates by submitting the following information to the Nominating and Corporate Governance Committee, c/o Corporate Secretary of First US Bancshares, Inc., 131 West Front Street, P.O. Box 249, Thomasville, Alabama 36784:

In addition to submitting nominations in advance to the Nominating and Corporate Governance Committee for consideration, a shareholder also may nominate persons for election to the Board of Directors in person at a shareholders meeting. Section 2.15 of the Company's Bylaws provides for procedures pursuant to which shareholders may nominate a candidate for election as a director of the Company. The chairperson of the meeting shall have the power to determine and declare to the meeting whether or not a nomination was made in accordance with the procedures set forth in our Bylaws and, if the chairperson determines that a nomination is

14

not in accordance with the procedures set forth in the Bylaws, to declare to the meeting that the nomination will be disregarded. A copy of the Company's Bylaws is filed as Exhibit 3.1 to our Current Report on Form 8-Kfiled with the SEC on January 30, 2025. We will furnish any person without charge, upon written request, a copy of the Bylaws. In addition to satisfying the requirements under our Bylaws, to comply with the SEC's universal proxy rules, stockholders who intend to solicit proxies in support of director nominees other than the Company's nominees must provide notice to the Company that complies with the informational and timing requirements of Rule 14a-19under the Exchange Act.

Shareholder Communications with the Board

The Board will give appropriate attention to written communications that are submitted by shareholders and will respond as the Board deems appropriate. Absent unusual circumstances or as contemplated by committee charters, the Chairperson of the Nominating and Corporate Governance Committee primarily will be responsible for monitoring communications from shareholders and providing copies or summaries of such communications to the other directors as he or she deems appropriate. Communications will be forwarded to all directors if such communications relate to substantive matters and include suggestions or comments that the Chairperson of the Nominating and Corporate Governance Committee considers important.

Shareholders and other interested parties who wish to send communications on any topic to the Board should address such communications to:

Chairperson of the Nominating and Corporate Governance Committee

c/o Corporate Secretary of First US Bancshares, Inc.

131 West Front Street

P.O. Box 249

Thomasville, Alabama 36784

All written communications to the Board will be relayed to the Nominating and Corporate Governance Committee without being screened by management.

15

TRANSACTIONS WITH RELATED PERSONS

The Company recognizes that transactions between the Company or its subsidiaries and any of its directors or executive officers may present potential or actual conflicts of interest that are not in the best interests of the Company and its shareholders. Therefore, as a general matter and in accordance with the Company's Code of Business Conduct and Ethics, the Company prefers to avoid such transactions. Nevertheless, there are situations where such transactions may be in, or may not be inconsistent with, the best interests of the Company and its shareholders. Therefore, the Company has adopted a written policy and procedures that require the Audit Committee to review and, if appropriate, to approve or ratify any such transactions.

Policy and Procedures Regarding Related Person Transactions

The Audit Committee's Policy and Procedures With Respect to Related Person Transactions sets forth the process for reviewing, approving and ratifying transactions involving the Company and its subsidiaries and "related persons." "Related persons" include directors, director nominees and executive officers and their immediate family members, and shareholders owning 5% or more of the Company's outstanding common stock and their immediate family members. It is the Company's policy to approve and ratify transactions involving related persons only when the Board, acting through the Audit Committee, determines that the transaction in question is in, or is not inconsistent with, the best interests of the Company and its shareholders.

The procedures provide that, prior to entering into a related person transaction, management or the affected director or executive officer must bring the matter to the attention of a designated individual who will assess whether the matter should be considered by the Audit Committee. If a member of the Audit Committee is involved in the proposed transaction, he or she will be recused from all discussions and decisions about the transaction. To the extent that a related person transaction is not identified in advance, the terms of the transaction will be reviewed and evaluated by the Audit Committee. Only transactions that are in, or that are not inconsistent with, the best interests of the Company and its shareholders are approved or ratified by the Audit Committee.

Certain Transactions with Related Persons

During the 2023 and 2024 fiscal years, the Company leased various properties from entities with which Mr. Tracy E. Thompson, one of the Company's current directors, is affiliated. Pursuant to those lease arrangements, the Company paid a limited liability company, of which Mr. Thompson is the sole member, $301,524 and $160,064 in 2023 and 2024, respectively. The Company's lease negotiations with Mr. Thompson's entities are negotiated on the same basis and subject to the same terms and conditions as the Company's other similar lease arrangements.

Certain directors and executive officers of the Company and their family members are customers of, and have had transactions with, the Bank in the ordinary course of business, and additional transactions likely will take place in the ordinary course of business. The federal securities laws generally prohibit the Bank from extending credit to its directors and executive officers. However, loans made by the Bank to its directors and executive officers in compliance with federal banking regulations are exempted from this prohibition. Federal banking regulations require that all loans or extensions of credit to directors and executive officers of insured institutions must be made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other persons and must not involve more than the normal risk of repayment or present other unfavorable features. The Bank, therefore, is prohibited from making any new loans or extensions of credit to directors and executive officers at different rates or terms than those offered to the general public.

All outstanding loans and commitments to date have been made in the ordinary course of business and on substantially the same terms, including with respect to interest rates and collateral, as for comparable transactions with unrelated persons, and have not involved more than the normal risk of repayment or presented other unfavorable features.

16

EXECUTIVE COMPENSATION

Compensation Philosophy and Objectives

This Executive Compensation section describes the 2024 executive compensation program for our named executive officers. Our primary objective is to achieve and sustain significant increases in shareholder value. We have designed our executive compensation program, and we routinely evaluate and consider modifications to the program, to support this objective with a strong link between pay and corporate and individual performance, while discouraging executives from taking excessive risks. Our approach is aimed at ensuring our ability to attract, retain and motivate the executives, managers and professionals who are critical to our short- and long-term success in the banking industry. A portion of our executives' compensation is "performance-based" in the form of incentives that are intended to motivate balanced decision-making by our executives while also aligning their interests with those of our shareholders.

We design our compensation program to align with the following principles:

Compensation Governance Best Practices

The Compensation Committee annually reviews best practices in executive compensation and governance and continues to enhance our policies and practices, which include the following:

17

Oversight of the Compensation Program

The Compensation Committee oversees our compensation program and approves the compensation paid to all executive officers, including the Chief Executive Officer and the two other most highly-compensated executive officers during 2024 - Mr. House, Mr. Elley and Mr. Mitchell (collectively, the "Named Executive Officers" or "NEOs").

Our Compensation Committee's responsibilities include reviewing and approving the amount, form and terms of compensation to be paid to the Named Executive Officers and assessing and making recommendations to the Board regarding executive compensation and benefit plans and programs. The Chief Executive Officer assists the Compensation Committee with determining the amount of compensation to be paid to the other executive officers but does not play a role in the final determination or approval of his own compensation. Our Human Resources Department also assists the Compensation Committee with compensation decisions by providing support and data for the committee.

Compensation Consultant

The charter of the Compensation Committee grants the Committee the authority to hire outside consultants to further its objectives and assist with its responsibilities. The Compensation Committee has engaged Willis Towers Watson, an independent compensation consultant, to assist the Compensation Committee by reviewing, assessing and providing recommendations with respect to the amount and form of director and executive officer compensation.

The Company does not have a policy that limits the services that an executive compensation consultant can perform. However, the Company has not engaged Willis Towers Watson for any projects other than those directed by the Compensation Committee and management, as described above, nor has Willis Towers Watson performed any other services for the Company. As a result, the Company has determined that Willis Towers Watson operates with full objectivity and without conflicts of interest in its support of the Compensation Committee.

Benchmarking

In determining market competitiveness of compensation, the Compensation Committee, with the assistance of Willis Towers Watson, reviews annually a combination of proxy information from the Company's compensation peer group and available market compensation survey data. The Compensation Committee may also use comparisons to the Company's compensation peer group to consider other market practices relevant to the scope of our executives' responsibilities. The Compensation Committee generally seeks to provide our executives with total compensation positioned around the median of competitive practice in order to assist in attracting and retaining talented executives and to further motivate and reward our NEOs for sustained, long-term improvements in the Company's financial results.

18

At the request of the Compensation Committee, Willis Towers Watson prepared an evaluation of our peer group for use in 2024. As a result of the evaluation, Willis Towers Watson recommended, and the Compensation Committee approved, the twelve companies listed below as the peer group for 2024. Willis Towers Watson identified and recommended these companies based on their being in a similar industry, being in a similar location and trading on the same stock exchange as the Company, as well as having assets between 0.5 and 2.0 times those of First US Bank.

Elements of Executive Compensation

Base Salaries

Each Named Executive Officer's base salary is determined principally by the responsibilities required by the officer's position, experience and contributions to our business and length of service in his position at the Company, as well as individual competence and comparison to peer institutions. Base salaries are reviewed and approved by the Compensation Committee annually to determine whether the base salary levels are appropriate. The base salaries of the Named Executive Officers in 2024 were as follows: for Mr. House, $400,000, increased from $390,000 in 2023; for Mr. Elley, $273,200, increased from $265,200 in 2023; and for Mr. Mitchell, $260,200, increased from $252,200 in 2023.

2024 Cash Incentive Program

In February 2024, the Company established a cash incentive program for certain executive officers and key employees of the Company and its subsidiaries designed to incentivize the achievement of specified short-term performance criteria (the "2024 CIP"). Under the 2024 CIP, each Named Executive Officer had the opportunity to eaa one-timecash payment equal to a predetermined percentage of his 2024 base salary, with the earned amount based on the level of performance with respect to certain corporate objectives applicable to the Company and the Bank. For Mr. House and Mr. Elley, the payment was based on (i) consolidated pre-taxincome of the Company, (ii) consolidated pre-taxretuon average assets, (iii) consolidated pre-taxretuon average tangible equity, and (iv) a discretionary component related to each executive's contributions toward the Company's strategic goals during 2024. For Mr. Mitchell, the payment was based on (a) consolidated pre-taxincome of the Company, (b) consolidated pre-taxretuon average assets, (c) consolidated pre-taxretuon average tangible equity, (d) net loan growth in indirect lending and (e) a discretionary component related to Mr. Mitchell's contributions toward the Company's strategic goals during 2024. The Company's 2024 performance targets are set forth in the table below.

19

Based on the performance metrics above, each Named Executive Officer was eligible to eathe payout amounts set forth in the table below.

Each Named Executive Officer's cash incentive payment was potentially subject to a downward adjustment as a result of certain regulatory or compliance ratings at the Bank.

Equity Awards

Our Named Executive Officers historically were eligible to participate in the First US Bancshares, Inc. 2013 Incentive Plan, which was originally adopted by the Board on March 22, 2013, and amended on May 2, 2019 (the "2013 Incentive Plan"). The 2013 Incentive Plan provided for the grant of incentive and nonqualified stock options, stock appreciation rights, awards of restricted stock and restricted stock units and performance compensation awards, including performance-based cash bonuses, to employees, non-employee directorsand certain consultants of the Company and its affiliates, including the Bank.

On February 22, 2023, the Board adopted the First US Bancshares, Inc. 2023 Incentive Plan (the "2023 Incentive Plan"), which was approved by the Company's shareholders on April 27, 2023. The 2023 Incentive Plan provides for the grant of the same types of awards as the 2013 Incentive Plan. The Compensation Committee intends to grant all future incentive awards under the 2023 Incentive Plan, and no additional grants will be made under the 2013 Incentive Plan.

20

SUMMARY COMPENSATION TABLE

The following table sets forth, for the years ended December 31, 2024 and 2023, a summary of the compensation paid to or earned by the Named Executive Officers. Note that, as a "smaller reporting company" and pursuant to the rules of the SEC, the Company is providing compensation information for 2024 and 2023 for Mr. House, as the President and Chief Executive Officer of the Company and the Bank, and Mr. Elley and Mr. Mitchell, as the two most highly compensated executive officers of the Company other than Mr. House who were serving as executive officers at the end of 2024.

24

OUTSTANDING EQUITY AWARDS AT 2024 FISCAL YEAR-END

The following table sets forth information as of December 31, 2024, concerning outstanding equity awards previously granted to our Named Executive Officers:

25

Employment Agreement with Mr. House

On December 19, 2013, Mr. House entered into an Amended and Restated Executive Employment Agreement (the "2013 Employment Agreement") with the Company and the Bank, which became effective on January 1, 2014, and replaced the employment agreement entered into by Mr. House with the Company and the Bank on November 7, 2011, when Mr. House first began serving as President and Chief Executive Officer of the Company and the Bank.

The initial term of the 2013 Employment Agreement was three years, with an additional year added to the term on each anniversary of the effective date, unless one of the parties provides notice of its intention not to extend the term. The 2013 Employment Agreement provides that Mr. House will be paid and eligible for the following compensation, among other employee benefits: an annual base salary that is subject to increase by the Board, life insurance coverage in the amount of $250,000, the use of a Company-owned automobile and reimbursement of reasonable expenses in operating such automobile, temporary housing in Thomasville, Alabama, and reimbursement of ordinary and reasonable expenses incurred in the performance of his duties as Chief Executive Officer and President of the Company and the Bank. In addition, for each year of the term of the 2013 Employment Agreement, Mr. House will be eligible to receive an annual long-term incentive award of up to 5,000 shares of the Company's common stock, options to purchase up to 10,000 shares of the Company's common stock, or some combination of the foregoing. The agreement also contains non-compete andconfidentiality restrictions. Specifically, Mr. House is prohibited from competing with the Company or the Bank for two (2) years following the termination of his employment and from disclosing confidential and proprietary information for a period of three (3) years after the termination of his employment.

Under the terms of the 2013 Employment Agreement, Mr. House is entitled to certain payments and benefits if his employment terminates due to his retirement, death or involuntary termination, or if his termination is related to a change in control of the Company or the Bank. In the event that Mr. House's employment terminates due to his death or disability, or Mr. House terminates his employment for any reason other than "good reason," he is entitled to any accrued and unpaid base salary earned through the date of termination and all vested amounts payable and vested benefits accrued under any otherwise applicable plan, policy, program or practice in which Mr. House was a participant. If Mr. House is involuntarily terminated without "cause" or Mr. House terminates his employment for "good reason," he is entitled to (i) a lump sum cash payment within thirty (30) days following his termination in an amount equal to the greater of either one (1) times his base salary then in effect or the amount of the base salary that otherwise would have been payable to Mr. House for the remainder of the term and (ii) reimbursement for any premiums paid by Mr. House for COBRA health continuation coverage, subject to limitations in the agreement. In the event of a change in control, Mr. House is not entitled to any payment unless he is terminated or he terminates his employment within six (6) months following the change in control. If Mr. House is terminated without "cause" or if he terminates his employment for "good reason" during the six (6) months following a change in control, he is entitled to a lump sum cash payment within thirty (30) days following his termination in an amount equal to 299% of his "base amount," as defined in Section 280G(b)(3)(A) of the Internal Revenue Code of 1986, as amended, subject to all applicable withholdings.

Internal Revenue Code Section 409A imposes significant taxes on an executive officer in the event that he receives deferred compensation that does not satisfy certain statutory and regulatory requirements in accordance with Internal Revenue Code Section 409A. However, it is the intent of the Company and the Bank that the amounts payable to Mr. House under the employment agreement comply with or are exempt from Section 409A.

Potential Payments Upon Termination or Change in Control

Mr. House's 2013 Employment Agreement contains severance provisions pursuant to which Mr. House is entitled to certain payments or benefits in the event that his employment is terminated without "cause" or for "good reason." See the discussion under "Employment Agreement with Mr. House" for additional information.

26

In addition, on May 20, 2014, the Company entered into Change in Control Agreements with its executive officers, including Mr. Elley, and on February 22, 2021, the Company entered into an Amended and Restated Change in Control Agreement with Mr. Mitchell. Subsequently, on March 1, 2022, the Company entered into an Amended and Restated Change in Control Agreement with certain of its executive officers, including Mr. Elley, and a Second Amended and Restated Change in Control Agreement with Mr. Mitchell (collectively, the "Amended CIC Agreements"). Each of the Amended CIC Agreements provides for an eighteen-month period following a "change in control" (as defined in the Amended CIC Agreements) during which the executive officer will be, upon experiencing a "qualifying termination of employment" (as defined in the Amended CIC Agreements), entitled to a one-timelump sum payment by the Company in an amount equal to 200% of the sum of (A) the executive officer's annual base salary in effect as of the date of termination plus (B) the executive officer's target bonus opportunity under the cash incentive program in effect for the year at issue (the "Severance Benefit"), a pro rata share of the executive officer's target bonus for the year in which termination occurs, and the reimbursement by the Company of health insurance continuation expenses incurred by the executive officer, in addition to any rights and welfare benefits provided to the executive officer under any plans and programs upon termination of employment. In the event that the executive officer's employment is terminated as a result of such officer's voluntary resignation without "good reason" (as defined in the Amended CIC Agreements) within six (6) months after a change in control, the executive officer will be entitled to the same payments described above, except that the one-timelump sum payment will be equal to 100% of the executive officer's Severance Benefit. Each of the Amended CIC Agreements also provides that, during the employment period and for a period of two (2) years following termination of employment, the executive officer will be bound by covenants not to compete and not to solicit customers or employees; provided, however, that the non-competitionprovisions of the Amended CIC Agreements will apply only if the executive officer is entitled to the one-time lumpsum payment described above; and, provided further, that if the executive officer is entitled to a lump sum payment equal to only 100% of the Severance Benefit, the non-competitionprovisions of the Amended CIC Agreements will endure for only one (1) year.

Pursuant to the restricted stock award agreements (each a "Restricted Stock Award Agreement") under the 2013 Incentive Plan and the 2023 Incentive Plan (collectively, the "Plans"), if an officer's Continuous Service (as defined in the Plans) terminates due to death, disability or retirement (as defined in the Restricted Stock Award Agreement), 100% of the unvested restricted stock shall vest as of the date of such termination. If the Continuous Service terminates for any reason other than death, disability or retirement, any unvested restricted stock shall be automatically forfeited upon such termination. Pursuant to the Plans, in the event of a Change in Control (as defined in the Plans) the Restricted Period (as defined in the Plans) shall expire immediately with respect to 100% of the shares of restricted stock, subject to the discretion of the Compensation Committee.

Pursuant to the nonqualified stock option agreements (each an "Option Agreement") under the Plans, in the case of termination due to disability, any unvested portion of the option shall become fully vested on the date of termination and the officer (or, in certain circumstances, his personal representative) may exercise the vested option at any time prior to the Expiration Date (as defined in the Option Agreement). In the case of termination due to death, any unvested portion of the option shall become fully vested on the date of death, and the vested option may be exercised by the officer's estate, by a person who acquired the right to exercise the option by bequest or inheritance, or by a person designated pursuant to the Option Agreement at any time prior to the Expiration Date. In the case of termination due to retirement (as defined in the Option Agreement), any unvested portion of the option shall become fully vested on the date of retirement and the officer may exercise the vested option at any time prior to the Expiration Date. In the case of termination other than for disability, death or retirement, the officer may exercise the vested portion of the option, but only within such period of time ending on the earlier of (a) the date three (3) months following the termination of the officer's continuous service or (b) the Expiration Date; provided, however, that in the case of termination for Cause (as defined in the Plans), the option (whether vested or unvested) shall immediately terminate and cease to be exercisable. In the case of a Change in Control, the option shall become immediately vested and exercisable with respect to 100% of the shares subject to the option, subject to the discretion of the Compensation Committee.

27

DIRECTOR COMPENSATION

In establishing director compensation, the Company considers the significant amount of time that directors expend in fulfilling their duties to the Company and the skill level required by the Company of members of the Board, as well as the importance of attracting and retaining qualified candidates to serve on the Board.

Fees

Each of the non-employeedirectors of the Company receives a $24,000 annual retainer for service as a director. If there is a non-executiveChairperson, he or she will receive an additional $10,000 annual retainer. If there is a Lead Independent Director, he or she will receive an additional $10,000 annual retainer. The Chairpersons of the committees of the Board receive additional retainer fees as follows: $7,500 annually for the Chairperson of the Audit Committee and $5,000 annually for the Chairperson of each of the following committees: the Asset/Liability Committee; the Compensation Committee; the Directors' Loan Committee; the Executive Committee; the Nominating and Corporate Governance Committee; the Information Technology Steering Committee; the Retail Operations Compliance Committee; and the Tennessee New Business Committee.

Equity Compensation

Our directors historically were eligible to participate in the 2013 Incentive Plan, under which they were able to receive grants of nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units and other types of equity awards designed to align the interests of the directors with those of the Company's shareholders. Pursuant to the First US Bancshares, Inc. Equity-Based Awards Grant Policy, the Compensation Committee determined the level of annual equity-based grants to be awarded with consideration given to each director's level of responsibility and total compensation as well as the value of any benefits to which a director is entitled under any retirement agreement with the Company, as discussed below.

On February 22, 2023, the Board adopted the 2023 Incentive Plan, which was approved by the Company's shareholders on April 27, 2023. The 2023 Incentive Plan provides for the grant of the same types of awards as the 2013 Incentive Plan. The Compensation Committee will grant all future incentive awards under the 2023 Incentive Plan, and no additional grants will be made under the 2013 Incentive Plan.

On February 9, 2024, the Compensation Committee awarded a total of 12,200 shares of restricted stock to our directors. The shares vested in full on the first anniversary of the grant date and, therefore, are no longer restricted. During the restricted period, the directors were entitled to vote and receive dividends with respect to their shares of common stock but could not transfer the shares, outside of certain narrow exceptions. The value of the grant of restricted stock to each director is set forth in the "2024 Director Compensation Table" below.

Stock Ownership Guidelines for Non-Employee Directors

We believe that it is important for our directors to have a financial stake in the Company, and we have adopted formal stock ownership guidelines for non-employee directors.Under the ownership guidelines, which are set forth in our Guidelines on Significant Governance Issues, the Board has specified a requirement that non-employeedirectors must own at least 400 shares of the Company's common stock. The guidelines further direct that each non-employeedirector should develop a meaningful ownership position in the Company over time. During 2024, all of our non-employeedirectors were in compliance with the ownership guidelines. Additional information regarding the beneficial stock ownership of our non-employeedirectors can be found in the "Security Ownership of Certain Beneficial Owners and Management" table contained herein.

Director Retirement Agreements

In order to encourage the members of the Board to continue to serve as directors of the Company, we entered into director retirement agreements with each of our non-employeedirectors who joined the Board prior to 2013. The director retirement agreements are nonqualified deferred compensation arrangements that are designed to motivate the directors to serve on the Board until their retirement.

31

We initially entered into the director retirement agreements in 2002 with each member of the Board at that time, including current directors Meigs and Wilson. In their original form, these agreements promised each director a benefit to be paid annually for ten years, generally beginning on the later of the date on which the director reached age 70 or the date on which the director terminated service as a director. The amount of the benefit was initially set at $12,000 in September 2002 and was scheduled to increase by 3% each year until the director reached age 70 or his or her service as a director was terminated. The benefit was to be reduced if the director retired from the Board before age 70 or terminated service as a director due to a disability before age 70.

The director retirement agreements provide a change in control benefit. We believe that the interests of the Company's shareholders will be best served if the interests of our directors are aligned with the shareholders' interests. Therefore, the director retirement agreements provide that, if a director is terminated following a change in control of the Company or a change in control of the Bank, we will pay the director annually for ten years, beginning at age 70, an amount equal to the maximum benefit that he or she would have been entitled to receive had the director terminated service as a director at age 70.

The director retirement agreements are subject to Internal Revenue Code Section 409A. On November 20, 2008, the Company and the Bank entered into amendments to the director retirement agreements for each director at the time, the purpose of which was to ensure that the terms of the director retirement agreements comply with Internal Revenue Code Section 409A so that the directors would avoid potential negative tax consequences. The amendments to the director retirement agreements did not materially change the scope or amount of benefits to which the directors are entitled but may affect the time and form of payment of such benefits. The director retirement agreement entered into by the director joining the Board subsequent to the November 2008 amendments but prior to 2013 (current director McPhearson) complies with Section 409A.

On January 25, 2017, the agreements with current directors Meigs and Wilson were again amended to reflect the increase in the mandatory retirement age for non-employeedirectors from age 70 to age 75. Specifically, the 2017 amendment clarified that the annual increases in the amount of the annual benefit payable pursuant to the agreement will terminate at the end of the plan year (commencing on September 1 and ending on August 31) immediately preceding the date of the first meeting of shareholders of the Company at which directors are elected, following the date on which the director reaches the mandatory retirement age set forth in the Company's Bylaws. No amendment was required to the agreement with current director McPhearson to reflect this clarification.

Equalization Stipend

Directors who joined the Board in 2013 or later have not entered into director retirement agreements. In order to alleviate pay discrepancies between directors who entered into director retirement agreements and those who did not, as well as to more equitably align the pay structure of all directors, beginning in 2021, an "equalization stipend" was paid in cash. This stipend served to fairly equalize the combination of all Board fees, stock awards, and changes in the accumulated benefit accruing under the director retirement agreements.

Deferral Plan

Non-employee directorsmay elect to defer payment of all or any portion of their fees earned as directors under the First US Bancshares, Inc. Non-Employee Directors'Deferred Compensation Plan (the "Deferral Plan"). The Deferral Plan, which was originally ratified at the Annual Meeting of the Company's shareholders held on May 11, 2004 and amended and restated by the Board effective July 1, 2023, permits non-employee directorsto invest their directors' fees and to receive the adjusted value of the deferred amounts in cash and/or shares of the Company's common stock. If the deferred amounts are invested in share units, the retuis determined as if such funds had been invested in the Company's common stock, and, if the deferred amounts are invested in cash, the retuis calculated at an interest rate equal to the one-monthterm Secured Overnight Financing Rate (SOFR) plus 75 basis points. Deferred amounts generally are distributed to a director at the termination of such individual's service as a director of the Company, either in a lump sum payment or in annual installment payments. During 2024, four of our non-employeedirectors (Messrs. Gordon, Hale, and Miller, and Ms. Cook) deferred some or all of their directors' fees under the Deferral Plan.

32

2024 Director Compensation Table

The following table provides information regarding compensation earned by or paid to the Company's non-employeedirectors in 2024.

33

COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION

The Compensation Committee consists of Bruce N. Wilson, Chairperson, J. Lee McPhearson, Jack W. Meigs, Aubrey S. Miller, and Staci M. Pierce. Pursuant to the Compensation Committee's charter, Mr. House, Chairperson of the Board, Chief Executive Officer and President of the Company, is permitted to be present at meetings during which executive compensation other than for himself is under review and consideration. No member of the Compensation Committee nor director during 2024 was an executive officer of another company with a board of directors that has a comparable committee on which one of our executive officers serves on either the board of directors or the comparable compensation committee. No member of our Compensation Committee during 2024 had any relationships requiring disclosure under Item 404 of Regulation S-K.

34

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth the number and percentage of outstanding shares of the Company's common stock beneficially owned as of March 12, 2025, by (i) the Named Executive Officers; (ii) each director and director nominee of the Company; (iii) all current executive officers and directors of the Company as a group; and (iv) beneficial owners of 5% or more of our common stock.

35

36

DELINQUENT SECTION 16(a) REPORTS

Section 16(a) of the Exchange Act requires our directors and officers, and persons who own more than ten percent (10%) of our common stock, to file reports of ownership and changes in ownership of Company common stock held by them with the SEC. Copies of these reports must also be provided to the Company. Based on our review of these reports, we believe that, during the year ended December 31, 2024, all reports required to be filed during such year were filed on a timely basis, with the exception of a late Form 4 filing on behalf of Eric H. Mabowitz filed on July 10, 2024, relating to the rebalancing of his 401(k) plan.

37

AUDIT COMMITTEE REPORT

The Audit Committee of the Board is composed of six directors who are independent directors as defined under the applicable Nasdaq listing rules and the SEC rules currently in effect.

The Audit Committee hereby submits the following report:

Based on the review and discussions referred to above, we recommended to the Board that the audited consolidated financial statements be included in the Company's Annual Report on Form 10-K forthe fiscal year ended December 31, 2024.

It should be noted that management is responsible for the Company's financial reporting process, including its system of internal controls, and the preparation of consolidated financial statements in accordance with accounting principles generally accepted in the United States of America. The Company's independent registered public accounting firm is responsible for auditing those consolidated financial statements. Our responsibility is to monitor and review this process. It is not our duty or our responsibility to conduct auditing or accounting reviews or procedures.

This report furnished by the Audit Committee:

Marlene M. McCain, Chairperson

Robert Stephen Briggs

Robert C. Field

Jack W. Meigs

Staci M. Pierce

Bruce N. Wilson

38

PROPOSAL 2

RATIFICATION OF APPOINTMENT OF

INDEPENDENT REGISTERED PUBLIC ACCOUNTANTS

At the direction of the Audit Committee, the ratification of the appointment of Carr, Riggs & Ingram, LLC ("Carr, Riggs & Ingram") as the Company's independent registered public accountants for the year ending December 31, 2025, is being presented to the shareholders for approval at the Annual Meeting. Although ratification is not required by our Bylaws or otherwise, the Board is submitting the selection of Carr, Riggs & Ingram to our shareholders for ratification as a matter of good corporate governance. If the selection is not ratified, the Audit Committee will consider whether it is appropriate to select another independent registered public accounting firm. Even if the selection is ratified, the Audit Committee in its discretion may select a different independent registered public accounting firm at any time during the year if it determines that such a change would be in the best interests of the Company and our shareholders.

General

The Audit Committee has approved the engagement of Carr, Riggs & Ingram as the Company's independent registered public accountants for the year ending December 31, 2025. Carr, Riggs & Ingram has served as the Company's principal accountants since August 7, 2008.

The Audit Committee reviews our independent registered public accountants' performance and independence. In connection with the Audit Committee's selection of Carr, Riggs & Ingram as our independent registered public accountants for 2025, the Audit Committee considered and discussed, among other factors:

Carr, Riggs & Ingram's partners who are assigned as "lead audit partners" for its audits of public companies are subject to a mandatory rotation policy, and a partner in the firm may not serve as lead audit partner for the firm's audit of our financial statements for more than five consecutive years. The Audit Committee does not approve or disapprove the accounting firm's assignment of a particular partner as lead audit partner, or its assignment of other members of the firm to its audit team, for audits of our financial statements. However, in connection with the Audit Committee's selection of our independent registered public accountants each year, the Audit Committee meets with the proposed lead audit partner, considers the partner's experience and performance on previous audits and any experience of the Audit Committee with the partner, and seeks and considers the views of our executive management. The Audit Committee then communicates its views regarding that partner to management of the accounting firm.

39

Based on its evaluation, the Audit Committee believes that Carr, Riggs & Ingram is independent and that it is in our and our shareholders' best interests to retain Carr, Riggs & Ingram as our independent registered public accountants for 2025.

A representative from Carr, Riggs & Ingram is expected to attend the Annual Meeting, will have the opportunity to make a statement if he or she desires to do so and is expected to be available to respond to appropriate questions.

Pre-Approval Policiesand Procedures

The Audit Committee of the Board has adopted policies and procedures for the pre-approval ofaudit and permissible non-audit servicesperformed by the independent registered public accountants. Pursuant to these policies and procedures, the Audit Committee generally is required to pre-approve theaudit and permissible non-audit servicesperformed by the independent registered public accountants in order to assure that the provision of such services does not impair the auditor's independence. Unless a type of service to be provided by the independent registered public accountants has received general pre-approval, theservice will require specific pre-approval bythe Audit Committee. Any proposed services exceeding pre-approved costlevels will require specific pre-approval bythe Audit Committee. On an annual basis, the Audit Committee may pre-approve specificservices that are expected to be provided to the Company by the independent registered public accountants during the following twelve months.

Audit and Other Service Fees

The following table sets forth the aggregate fees billed to the Company for the audit and other services provided by Carr, Riggs & Ingram for 2024 and 2023.

Audit Fees

Audit fees were for professional services rendered relating to the audit of the Company's annual consolidated financial statements and the review of financial statements included in the Company's Forms 10-Q andForm 10-K. Allof these services were pre-approved bythe Audit Committee.

Audit-Related Fees

Audit-related fees were for professional services rendered that are reasonably related to the performance of the audit or review of the Company's consolidated financial statements and are not reported under "Audit Fees." These fees represent the aggregate fees billed for services relating to attestation services related to financial reporting and for services relating to the employee benefit plan audit for 2024. These fees represent the aggregate fees billed for services relating to the employee benefit plan audit for 2023. All of these services were pre-approved bythe Audit Committee.

Tax Fees

Tax fees represent the fees billed for services relating to tax compliance, tax advice and tax planning. All of these services were pre-approved bythe Audit Committee.

All Other Fees

There were no other fees paid to Carr, Riggs & Ingram for 2024 and 2023.

40

Vote Required; Board Recommendation

The affirmative vote of a majority of the shares represented at the Annual Meeting in person or by proxy and entitled to vote on this matter is needed to ratify the appointment of Carr, Riggs & Ingram as the Company's independent registered public accountants for the year ending December 31, 2025. Unless instructed to the contrary, the shares represented by proxy will be voted FOR this proposal.

THE BOARD RECOMMENDS THAT YOU VOTE FOR THE RATIFICATION OF THE APPOINTMENT OF CARR, RIGGS & INGRAM AS THE COMPANY'S INDEPENDENT REGISTERED PUBLIC ACCOUNTANTS FOR THE YEAR ENDING DECEMBER 31, 2025.

41

PROPOSAL 3

ADVISORY APPROVAL OF EXECUTIVE COMPENSATION

The Dodd-Frank Wall Street Reform and Consumer Protection Act, enacted in July 2010, requires that companies provide shareholders with the opportunity to vote to approve, on a non-binding, advisorybasis, the compensation of their named executive officers in accordance with the compensation disclosure rules of the SEC. We intend to hold such an advisory vote on the compensation of our Named Executive Officers, commonly known as a "say-on-pay" vote,each year in connection with our annual meeting of shareholders until the next vote on the frequency of the "say-on-pay" voteor until the Board otherwise determines that a different frequency for this advisory vote is in the best interests of our shareholders. The next advisory vote on the frequency of future "say-on-pay"votes will occur no later than 2029.

As described in detail under the heading "Executive Compensation," we believe that the compensation of our executive officers should link rewards to business results and shareholders' returns. We believe that our compensation program should attract, retain and motivate the executive officers necessary for our current and long-term success and should provide the executive officers with a stake in the future of the Company that corresponds to the stake of each of our shareholders.

The vote on this resolution is not intended to address any specific element of compensation; rather, the vote relates to the compensation of our Named Executive Officers, as described in this Proxy Statement in accordance with the compensation disclosure rules of the SEC. The vote is advisory, which means that the vote is not binding on the Company, the Board or the Compensation Committee of the Board. To the extent that there is any significant vote against our Named Executive Officer compensation as disclosed in this Proxy Statement, the Compensation Committee will evaluate whether any actions are necessary to address the concerns of shareholders.

The affirmative vote of a majority of the shares represented at the Annual Meeting in person or by proxy and entitled to vote on this matter is required for the adoption of this Proposal, the results of which will be non-binding andadvisory in nature.

Accordingly, pursuant to Section 14A of the Exchange Act, we ask our shareholders to vote on the following resolution at the Annual Meeting:

"RESOLVED, that the Company's shareholders approve, on an advisory basis, the compensation of the Named Executive Officers, as disclosed in the Company's Proxy Statement for the 2025 Annual Meeting of Shareholders pursuant to the compensation disclosure rules of the SEC, including the 'Executive Compensation' section, the 'Summary Compensation Table' and the other related tables and disclosure."

THE BOARD RECOMMENDS THAT YOU VOTE FOR THE APPROVAL OF THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS, AS DISCLOSED IN THIS PROXY STATEMENT.

42

SHAREHOLDER PROPOSALS FOR 2026 ANNUAL MEETING

If any shareholder wishes to present a proposal to be included in the proxy materials for the Company's 2026 Annual Meeting of Shareholders, the shareholder must comply with applicable securities regulations, including providing adequate notice to the Company. Such proposals must be received by the Company at the address noted below on or before November 27, 2025, in order to be considered for inclusion in the Company's proxy materials relating to such meeting. If the date of the 2026 Annual Meeting changes by more than 30 days from May 1, 2026, then the deadline to submit stockholder proposals for inclusion in the proxy statement for the 2026 Annual Meeting will be a reasonable time before the Company begins to print and mail its proxy materials for the 2026 Annual Meeting. The Company will determine whether to include a proposal in the 2026 proxy statement in accordance with the SEC rules governing the solicitation of proxies.

If a stockholder proposal is submitted outside the proposal process mandated by SEC Rule 14a-8,and is submitted instead under the Company's advance notice Bylaw provision (Section 2.15 of the Bylaws), the proposal must be received by the Company's Corporate Secretary not earlier than January 1, 2026 nor later than January 31, 2026, together with the necessary supporting documentation required under that Bylaw provision. If the date of the 2026 Annual Meeting is advanced by more than 30 days or is delayed by more than 60 days from May 1, 2026, then to be timely the nomination or proposal must be received by the Company no earlier than the 120^th day prior to the 2026 Annual Meeting and no later than the close of business on the later of the 90^th day prior to the meeting or the 10^th day following the day on which public announcement of the date of the 2026 Annual Meeting is first made.

In addition to satisfying the requirements under our Bylaws, to comply with the SEC's universal proxy rules, stockholders who intend to solicit proxies in support of director nominees other than the Company's nominees at the 2026 Annual Meeting must provide notice to the Company that complies with the informational requirements of Rule 14a-19under the Exchange Act.

Any proposal must be submitted in writing, by certified mail, retureceipt requested, to:

Beverly J. Dozier, Corporate Secretary

First US Bancshares, Inc.

131 West Front Street

Post Office Box 249

Thomasville, Alabama 36784

OTHER MATTERS

We do not know of any matters to be presented for action at the Annual Meeting other than those set forth in the notice of the Annual Meeting and discussed in this Proxy Statement.

SEC rules permit companies and intermediaries such as brokers to satisfy delivery requirements for proxy statements and notices with respect to two or more shareholders sharing the same address by delivering a single proxy statement or a single notice addressed to those shareholders. Each shareholder continues to receive a separate proxy card. This process, commonly referred to as "householding," provides cost savings for companies. Some brokers household proxy materials, delivering a single proxy statement or notice to multiple shareholders sharing an address, unless contrary instructions have been received from the affected shareholders. Once you have received notice from your broker that they will be householding materials to your address, householding will continue until you are notified otherwise or until you revoke your consent. If, at any time, you no longer wish to participate in householding and would prefer to receive a separate proxy statement or notice, please notify your broker.

43

The Company will furnish to shareholders without charge, upon written or oral request, a copy of the Company's Annual Report on Form 10-K, includingthe accompanying financial statements and schedules, required to be filed with the Securities and Exchange Commission for the year ended December 31, 2024. Copies of the exhibits to the Form 10-K alsowill be available upon request. Requests should be made to:

Beverly J. Dozier, Corporate Secretary

First US Bancshares, Inc.

131 West Front Street

Post Office Box 249

Thomasville, Alabama 36784

Tel. (334) 636-5424

44

qIF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE.q

When shares are held by joint tenants, both should sign. Executors, administrators, trustees, etc. should give full title as such. If the signer is a corporation, please sign full corporate name by duly authorized officer. If the signer is a partnership, limited liability company or other entity, please sign full entity name by authorized person.

FIRST US BANCSHARES, INC. - ANNUAL MEETING MAY 1, 2025

YOUR VOTE IS IMPORTANT!

Annual Meeting materials are available online at:

www.edocumentview.com/FUSB

You can vote by proxy in one of three ways:

1. Via the Internet at www.envisionreports.com/FUSBand follow the instructions.

or

2. Call toll free 1-800-652-VOTE(8683) on a touch-tone telephone.

or

3. Mark, date and sign your proxy card, and retuit promptly in the enclosed postage-paid envelope.

PLEASE SEE REVERSE SIDE FOR VOTING INSTRUCTIONS

(Continued, and to be marked on the reverse side and dated and signed below)

The 2025 Annual Meeting of Shareholders of First US Bancshares, Inc. will be held on

Thursday, May 1, 2025, 10:00 A.M. Central Time, virtually via the internet at https://meetnow.global/MZ6SKCF

To access the virtual meeting, you must have the information that is printed in the shaded bar

located on the reverse side of this form.

qIF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE.q

qIF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE.q

When shares are held by joint tenants, both should sign. Executors, administrators, trustees, etc. should give full title as such. If the signer is a corporation, please sign full corporate name by duly authorized officer. If the signer is a partnership, limited liability company or other entity, please sign full entity name by authorized person.

FIRST US BANCSHARES, INC. - ANNUAL MEETING MAY 1, 2025

YOUR VOTE IS IMPORTANT!

Annual Meeting materials are available online at:

www.edocumentview.com/FUSB

You can vote by proxy in one of three ways:

PLEASE SEE REVERSE SIDE FOR VOTING INSTRUCTIONS

(Continued, and to be marked on the reverse side and dated and signed below)

qIF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE.q

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting:

The combined document is available at www.proxyvote.com.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -