KIRBY CORP

Disclosure Controls and Procedures. The Company’s management, with the participation of the Chief Executive Officer and the Chief Financial Officer, has evaluated the Company’s disclosure controls and procedures (as defined in Rule 13a-15(e) under the Securities Exchange Act of 1934 (“Exchange Act”)), as of December 31, 2023, as required by Rule 13a-15(b) under the Exchange Act. Based on that evaluation, the Chief Executive Officer and the Chief Financial Officer concluded that, as of December 31, 2023, the disclosure controls and procedures were effective to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act (i) is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms and (ii) is accumulated and communicated to the Company’s management, including the Chief Executive Officer and the Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

Management’s Annual Report on Internal Control Over Financial Reporting. Management of the Company is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act). The Company’s management, with the participation of the Chief Executive Officer and the Chief Financial Officer, evaluated the effectiveness of the Company’s internal control over financial reporting as of December 31, 2023 using the framework in Internal Control — Integrated Framework (2013)issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on that evaluation, management concluded that the Company’s internal control over financial reporting was effective as of December 31, 2023. KPMG LLP, the Company’s independent registered public accounting firm, has audited the Company’s internal control over financial reporting, as stated in their report which is included herein.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Changes in Internal Control Over Financial Reporting. There were no changes in the Company’s internal control over financial reporting during the quarter ended December 31, 2023 that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.