Prospectus by Investment Company (Form 497)

Supplement dated May 1, 2026 to the Statement of Additional Information ("SAI") dated June 30, 2025, of: OSTERWEIS FUND - OSTFX OSTERWEIS STRATEGIC INCOME FUND - OSTIX OSTERWEIS GROWTH & INCOME FUND - OSTVX OSTERWEIS OPPORTUNITY FUND - OSTGX

(the "Funds")

a series of Professionally Managed Portfolios (the "Trust")

Effective April 3, 2026, Mr. Jason Hadler resigned from his roles as President and Principal Executive Officer of the Trust. All references in the SAI to Mr. Hadler should be disregarded. Also effective April 3, 2026, the Board of Trustees of the Trust appointed Mr. Craig Benton to serve as the new President and Principal Executive Officer of the Trust and Ms. Kathryn LaPlante-Johnson to serve as the new Treasurer, Vice President, Principal Financial and Accounting Officer.

Accordingly, the lower table in the "Trustees and Officers" section of the SAI is hereby removed and replaced with the following:

Name, Year of Birth and Address

Position with the Trust

Term of Office and Length of Time Served

Principal Occupation During Past Five Years

Number of Portfolios in Fund Complex Overseen by Trustees

Other Directorships Held During the Past 5 Years

Officers of the Trust

Craig Benton (born 1985) c/o U.S. Bank Global Fund Services 615 East Michigan Street Milwaukee, WI 53202

President & Principal Executive Officer

Indefinite Term; Since April 2026.

Assistant Vice President, U.S. Bank Global Fund Services since November 2007.

Not Applicable.

Not Applicable.

Elaine E. Richards (born 1968) c/o U.S. Bank Global Fund Services 615 East Michigan Street Milwaukee, WI 53202

Secretary & Vice President

Indefinite Term; Since September 2024.

Senior Vice President, U.S. Bank Global Fund Services since July 2007.

Not Applicable.

Not Applicable.

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Kathryn E. LaPlante Johnson (born 1998) c/o U.S. Bank Global Fund Services 615 East Michigan Street Milwaukee, WI 53202

Treasurer, Vice President, Principal Financial Officer & Principal Accounting Officer

Indefinite Term; Since April 2026.

Mutual Funds Administrator, U.S. Bank Global Fund Services since June 2020.

Not Applicable.

Not Applicable.

Nicholas A. Moll (born 1998) c/o U.S. Bank Global Fund Services 615 East Michigan Street Milwaukee, WI 53202

Assistant Treasurer

Indefinite Term; Since November 2024.

Mutual Funds Administrator, U.S. Bank Global Fund Services since December 2022.

Not Applicable.

Not Applicable.

Keana Hang (born 1999) c/o U.S. Bank Global Fund Services 615 East Michigan Street Milwaukee, WI 53202

Assistant Treasurer

Indefinite Term; Since May 2025.

Mutual Funds Administrator, U.S. Bank Global Fund Services since February 2022.

Not Applicable.

Not Applicable.

Gazala Khan (born 1969) c/o U.S. Bank Global Fund Services 615 East Michigan Street Milwaukee, WI 53202

Chief Compliance Officer Anti-Money Laundering Officer

Indefinite Term; Since November 2022.

Vice President and Compliance Officer, U.S. Bank Global Fund Services since July 2022; Chief Compliance Officer Matthews Asia Fund (May 2019-July 15, 2022); Chief Compliance Officer GS Trust/VIT (June 2009-May 2019); Vice President GSAM (May 2005-June 2009); Staff Accountant, SEC Office of Compliance Inspection and Examination (1999-2005).

Not Applicable.

Not Applicable.

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Please retain this supplement with your SAI for future reference.

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