FORM 11-K [X]ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year endedDecember31, 2025 OR [ ]TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from…………………………to………………………..Commission file number………..001-14423………… A. Full title of the plan and the address of the plan, if different from that of the issuer named below: PLEXUS CORP. 401(k) RETIREMENT PLAN B. Name of issuer of the securities held pursuant to the plan and the address of its principal executive office: Plexus Corp.401(k) Retirement PlanFinancial Statements and Supplemental Schedule December 31, 2025 and 2024 Plexus Corp.401(k) Retirement PlanIndex to Financial Statements PageReport of Independent Registered Public Accounting Firm2Financial StatementsStatements of Net Assets Available for Benefits3Statement of Changes in Net Assets Available for Benefits4Notes to Financial Statements5Supplemental ScheduleSchedule H, Part IV, Line 4i: Schedule of Assets (Held at End of Year)11Signatures12 Other supplemental schedules required by the Employee Retirement Income Security Act have been omitted because theyare not applicable to the Plexus Corp. 401(k) Retirement Plan. Report of Independent Registered Public Accounting Firm To the Plan Administrator and Plan ParticipantsPlexus Corp. 401(k) Retirement PlanNeenah, Wisconsin Opinion on the Financial StatementsWe have audited the accompanying statements of net assets available for benefits of Plexus Corp. 401(k) Retirement Plan (the Plan) as of December 31, 2025 and 2024, and the related statement of changes in net assets available for benefits for the year ended December 31,2025, and the related notes (collectively referred to as the "financial statements"). In our opinion, thefinancial statements present fairly,in all material respects, the net assets available for benefits of the Plan as of December 31, 2025 and 2024, and the changes in net assetsavailable for benefits for the year ended December 31, 2025, in conformity with accounting principles generally accepted in the UnitedStates of America. Basis for OpinionThesefinancial statements are the responsibility of the Plan’s management. Our responsibility is to express an opinion on the Plan’s financial statements based on our audits. We are a public accountingfirm registered with the Public Company Accounting OversightBoard (United States) (PCAOB) and are required to be independent with respect to the Plan in accordance with the U.S. federal securitieslaws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the auditsto obtain reasonable assurance about whether thefinancial statements are free from material misstatement, whether due to error orfraud. The Plan is not required to have, nor were we engaged to perform, an audit of its internal control overfinancial reporting. As partof our audits, we are required to obtain an understanding of internal control overfinancial reporting but not for the purpose ofexpressing an opinion on the effectiveness of the Plan’s internal control overfinancial reporting. Accordingly, we express no suchopinion. Our audits included performing procedures to assess the risks of material misstatement of thefinancial statements, whether due toerror or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidenceregarding the amounts and disclosures in thefinancial statements. Our audits also included evaluating the accounting principles usedand significant estimates made by management, as well as evaluating the overall presentation of thefinancial statements. We believethat our audits provide a reasonable basis for our opinion. Supplemental InformationThe supplemental information in the accompanying Schedule H, Line 4i – Schedule of Assets (Held at End of Year) as of December 31, 2025,has been subjected to audit procedures performed in conjunction with the audit of the Plan’s financial statements. Thesupplemental information is the responsibility of the Plan’s management. Our audit procedures included determining whether thesupplemental information reconciles to thefinancial statements or the underlying accounting and other records, as applicable, andperforming procedures to test the completeness and accuracy of the information presented in the supplemental information. In formingour opinion on the supplemental information, we evaluated whether the supplemental information, including its form and content, ispresented in conformity with the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the EmployeeRetirement Income Security Act of 1974. In our opinion, the supplemental information is fairly stated, in all material respects, in relationto thefinancial