SIMMONS FIRST NATIONAL CORP

Code of Ethics — General. The Company has adopted a general Code of Ethics applicable to all directors, advisory directors, officers, and associates of the Company. The Code of Ethics is designed to promote conducting the business of the Company in accordance with the highest ethical standards of conduct and to promote the ethical handling of conflicts of interest, full and fair disclosure, and compliance with laws, rules, and regulations. Additionally, under the Code of Ethics, directors, advisory directors, officers, and associates who learn of a business opportunity in the course of their service for the Company generally cannot appropriate that opportunity for themselves or for others, but must allow the Company to take advantage of the opportunity. The Company’s Code of Ethics is designed to provide guidance and resources to help ensure that:

• The Company and its directors, advisory directors, officers, and associates comply with applicable laws and regulations;

• The Company’s assets are used efficiently and appropriately;

• Confidential and proprietary information is protected;

• The Company’s directors, advisory directors, officers, and associates comply with the Company’s Insider Trading Policy, as well as the laws, rules, and regulations that regulate transactions in the Company’s stock;

• Inappropriate gifts or favors are not accepted; and

• Actual or perceived conflicts of interest are appropriately addressed.

Any material departure from a provision of the Code of Ethics by a director, advisory director, officer, or associate may be waived by the Ethics Committee (in the case of an officer or associate (other than an executive officer)) or the NCGC (in the case of a director, advisory director, or executive officer) and shall, as appropriate, be reported to the Board, and any such waiver will be promptly disclosed on its website to the extent required by applicable law, rule, or regulation. The Company will disclose any amendments with respect to its Code of Ethics on its website.

Code of Ethics for Finance Group. The Board has adopted a separate Finance Group Code of Ethics that supplements the Code of Ethics and applies to the Company’s Chief Executive Officer, Chief Financial Officer, Chief Accounting Officer, Controller and all other officers and associates in the Finance and Accounting, Treasury,

and Tax Departments of the Company and its subsidiaries. To the extent required by applicable law, rule, or regulation, the Company will disclose any amendments or waivers with respect to its Finance Group Code of Ethics on its website.

Both of these Codes of Ethics may be found on the Company’s website atwww.simmonsbank.com within the “Investor Relations” page under “ESG — Governance — Governance Documents”.