8-K   UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549   FORM 8-K   CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 03, 2026     OLD DOMINION FREIGHT LINE, INC. (Exact name of Registrant as Specified in Its Charter)     Virginia 0-19582 56-0751714 (State or Other Jurisdiction of Incorporation) (Commission File Number) (IRS Employer Identification No.)           500 Old Dominion Way   Thomasville , North Carolina   27360 (Address of Principal Executive Offices)   (Zip Code)   Registrant’s Telephone Number, Including Area Code: (336) 889-5000   Not Applicable (Former Name or Former Address, if Changed Since Last Report)   Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class   Trading Symbol(s)   Name of each exchange on which registered Common Stock ($0.10 par value)   ODFL   The Nasdaq Stock Market LLC Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐   Item 7.01 Regulation FD Disclosure. On September 3, 2026, Old Dominion Freight Line, Inc. issued a press release to provide an update on certain operating metrics for the third quarter of 2026. A copy of this press release is furnished as Exhibit 99.1. Item 9.01 Financial Statements and Exhibits. Exhibit No.   Description 99.1   Press Release dated September 3, 2026 104   Cover Page Interactive Data File (embedded within the Inline XBRL document)   SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.     OLD DOMINION FREIGHT LINE, INC.             By: /s/ Clayton G. Brinker       Clayton G. Brinker       Vice President - Accounting and Finance       (Principal Accounting Officer) Date: September 3, 2026