It said: "On behalf of the O'Sullivan family, it is with profound sadness that the IHRB confirms the passing of Michael O'Sullivan.
The National Hunt jockey passed away following a tragic fall at the Thurles Racecourse on February 6.
O'Sullivan was airlifted to the Cork University Hospital after the incident, which involved five horses.
He remained in intensive care until it was announced that he died on Sunday morning.
The IHRB released a statement sending condolences to his family.
