Prospectus Supplement

John Hancock Funds III

John Hancock Disciplined Value Mid Cap Fund (the fund)

Supplement dated March 31, 2023 to the current Prospectus, as may be supplemented (the Prospectus)

As of December 31, 2023 (the Effective Date), Joseph F. Feeney, Jr. will no longer serve as a portfolio manager for the fund. Accordingly, as of the Effective Date, all references to Mr. Feeney will be removed from the Prospectus.

As of the Effective Date, Timothy P. Collard and Steven L. Pollack, CFA will continue to serve as portfolio managers and be jointly and primarily responsible for the day-to-day management of the fund’s portfolio.

You should read this supplement in conjunction with the Prospectus and retain it for your future reference.

Manulife, Manulife Investment Management, Stylized M Design, and Manulife Investment Management & Stylized M Design are trademarks of The Manufacturers Life Insurance Company and are used by its affiliates under license.

Statement of Additional Information Supplement

John Hancock Funds III

John Hancock Disciplined Value Mid Cap Fund (the fund)

Supplement dated March 31, 2023 to the current Statement of Additional Information, as may be supplemented (the SAI)

As of December 31, 2023 (the Effective Date), Joseph F. Feeney, Jr. will no longer serve as a portfolio manager for the fund. Accordingly, as of the Effective Date, all references to Mr. Feeney will be removed from the SAI.

As of the Effective Date, Timothy P. Collard and Steven L. Pollack, CFA will continue to serve as portfolio managers and be jointly and primarily responsible for the day-to-day management of the fund’s portfolio.

You should read this supplement in conjunction with the SAI and retain it for your future reference.

Manulife, Manulife Investment Management, Stylized M Design, and Manulife Investment Management & Stylized M Design are trademarks of The Manufacturers Life Insurance Company and are used by its affiliates under license.