THE RBB FUND, INC.

Adara Smaller Companies Fund (the “Fund”)

______________________________________________________________________

Supplement dated May 16, 2025

to the Prospectus and Statement of Additional Information (“SAI”)

dated December 31, 2024

______________________________________________________________________

Effective June 2, 2025, the mailing address for the Fund has changed. Going forward, please send written requests to obtain Fund documentation, or to purchase, redeem, or exchange shares of the Fund to:  

Regular Mail:

Adara Smaller Companies Fund

c/o U.S. Bank Global Fund Services 

PO Box 219252 

Kansas City, MO 64121-9252 

Overnight Delivery: 

Adara Smaller Companies Fund

c/o U.S. Bank Global Fund Services 

801 Pennsylvania Ave, Suite 219252 

Kansas City, MO 64105-1307 

If you have any questions, please call the Funds at 1-844-261-6482.

Investors should retain this supplement for future reference.

THE RBB FUND, INC.

Aquarius International Fund (the “Fund”)

______________________________________________________________________

Supplement dated May 16, 2025

to the Prospectus and Statement of Additional Information (“SAI”)

dated December 31, 2024

______________________________________________________________________

Effective June 2, 2025, the mailing address for the Fund has changed. Going forward, please send written requests to obtain Fund documentation, or to purchase, redeem, or exchange shares of the Fund to:  

Regular Mail:

Aquarius International Fund

c/o U.S. Bank Global Fund Services 

PO Box 219252 

Kansas City, MO 64121-9252 

Overnight Delivery: 

Aquarius International Fund

c/o U.S. Bank Global Fund Services 

801 Pennsylvania Ave, Suite 219252 

Kansas City, MO 64105-1307 

If you have any questions, please call the Fund at 1-844-261-6482.

Investors should retain this supplement for future reference.