A message from his family said that after “a trojan battle” to recover from his injuries in the intensive care unit of Cork University Hospital, O’Sullivan died on February 16 – a few days short of his 25th birthday.
“Michael will be very sadly missed by Bernie, William, Alan, grandmother ‘Granny Mary’, aunts, uncles, cousins, Charlotte, his many friends as well as his weigh-room colleagues and the wider racing community.”.
It said he had died surrounded by his heartbroken parents Bernie and William, brother Alan, partner Charlotte and extended family.
O’Sullivan shot to prominence when riding a double on the opening day of the 2023 Cheltenham Festival, headlined by his Supreme Novices’ Hurdle success on Marine Nationale, just months after turning professional.
The official notice was posted online on Sunday evening, along with a tribute from his family in which they spoke of their pride in an “extraordinary young man”.
