(Mark One)þANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the fiscal year ended December 31, 2025oroTRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the transition period fromtoCommission file number: 0-10546 DISTRIBUTION SOLUTIONS GROUP, INC. (Exact name of registrant as specified in its charter) Name of each exchange on which registered (NASDAQ Global Select Market) Securities registered pursuant to Section 12(g) of the Act:None(Title of class) Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YesoNoþIndicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. YesoNoþ Indicate by check mark whether the registrant (l) has filed all reports required to be filed by section 13 or 15(d) of the Securities Exchange Act of 1934 during thepreceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for thepast 90 days. YesþNoo Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of RegulationS-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). YesþNoo Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerginggrowth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2of the Exchange Act. Accelerated filerþSmaller reporting companyoEmerging growth companyo Large accelerated fileroNon-accelerated filero 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 orrevised financial accounting standards provided pursuant to Section 13(a) of the Exchange Acto Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control overfinancial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its auditreport.þ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filingreflect the correction of an error to previously issued financial statements.o Indicate by check mark whether the registrant is a shell company (as defined by Rule 12b-2 of the Act). YesoNoþ The aggregate market value of the registrant’s voting stock held by non-affiliates on June 30, 2025, based upon the closing price of the registrant’s Common Stockon that date, was approximately $258,112,845. As of February 27, 2026, 46,186,293 shares of common stock were outstanding. DOCUMENTS INCORPORATED BY REFERENCE Part III of this Annual Report on Form 10-K incorporates by reference certain portions of the registrant’s definitive proxy statement related to its 2026 AnnualStockholders’ Meeting, to be filed with the Securities and Exchange Commission within 120 days after the close of the fiscal year. Except as expresslyincorporated by reference, the registrant’s definitive proxy statement shall not be deemed to be part of this report. TABLE OF CONTENTS Cautionary Statement Regarding Forward-Looking Statements3 PART I Item 1.BusinessItem 1A.Risk FactorsItem 1B.Unresolved Staff CommentsItem 1C.CybersecurityItem 2.PropertiesItem 3.Legal ProceedingsItem 4.Mine Safety Disclosures PART II Item 5.Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases ofEquity Securities25Item 6.[RESERVED]26Item 7.Management’s Discussion and Analysis of Financial Condition and Results of Operations27Item 7A.Quantitative and Qualitative Disclosures About Market Risk39Item 8.Financial Statements and Supplementary Data40Item 9.Changes in and Disagreements with Accountants on Accounting and Financial Disclosure86Item 9A.Controls and Procedures87Item 9B.Other Information89Item 9C.Disclosure Regarding Foreign Jurisdictions that Prevent Inspections89 PART III Item 10.Directors, Executive Officers and Corporate Governance90Item 11.Executive Compensation90Item 12.Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters91Item 13.Certain Relationships and Related Transactions, and Director Independence91Item 14.Principal Accountant Fees and Services91 PART IV Item 15.Exhibits and Financial Statement Schedules92Item 16.Form 10-K Summary94Signatures95 CAUTIONARY STATEMENT REGARDING FORWARD LOOKING STATEMENTS This Annual Report on Form