Barry Connell described Michael O’Sullivan as a “bright, rising star” who leaves a lasting legacy following news of his death on Sunday at the age of 24.
The Cheltenham Festival-winning rider was airlifted to hospital following a fall at Thurles on February 6 and had remained in the intensive care unit at Cork University Hospital since.
O’Sullivan hit the big time when partnering the O’Connell-trained Marine Nationale to win the 2023 Supreme Novices’ Hurdle at Cheltenham, with the pair striking up a partnership when the rider was still a claiming amateur.
Marine Nationale pounces to win the Sky Bet Supreme Novices' Hurdle
It's a first win at the Cheltenham Festival for @Michael_OSull#ITVRacing | #CheltenhamFestival pic.twitter.com/LcpsQz4vTB
— ITV Racing (@itvracing) March 14, 2023
Connell told the PA news agency: “He was a bright, rising star as a jockey and we were lucky to have had a very close association with him.
“Everybody in the yard is devastated. He was such a lovely personality to have around the place, he fitted in really well. He was widely liked by his colleagues and everyone who met him.
“He didn’t work full time for us, he came in three days a week and he had other connections he rode for after he turned professional, but he was a pleasure to have around the place and everyone got on really well with him.
“I think everyone in racing is stunned today and all we can do is express our sympathy to his parents, William and Bernadette, and his brother, Alan. He will be sadly missed.”

Connell recalled how O’Sullivan had contacted him to ride future star Marine Nationale on his bumper debut in May 2022, with the then 7lb claimer steering him to a clear-cut victory and impressing the trainer in the process.
Marine Nationale won another bumper for the pair before embarking on a dream novice hurdling season that encompassed two Grade One victories, including on the opening day of the Festival when O’Sullivan also rode the Gordon Elliott-trained Jazzy Matty to win the Boodles Juvenile Handicap Hurdle for a dream double.
Connell said: “I think in early 2022 he’d ridden one point-to-point winner for me before and we had Marine Nationale running in a bumper. We didn’t have an amateur at the time and Michael was a 7lb-claiming amateur, he rang for the ride, we said fine and he won on the horse.
“We were very impressed with him so he came into the yard and started out riding a few days a week. We quickly decided Michael’s talent was very special and he got the job full time riding for us.

“Things happened very quickly after that, he turned professional in September. A matter of weeks after he turned pro, he rode a Grade Two winner for us on Enniskerry as a claimer and then rode Marine Nationale in the Royal Bond in December and gave him a wonderful ride.
“He had a great partnership with the horse which culminated in the Supreme Novices’ and it was fairytale stuff for both myself and Michael on a journey together with the horse.
“Despite being a claimer and having limited experience of Cheltenham, he gave the horse a masterful ride and the icing on the cake was he got a spare ride later in the day and had a double.
“The following day he was in the parade ring to ride Good Land in the other Grade One and one of the officials came out with the golden armband and gave it to me and said ‘put that on Michael’, so he was the leading rider after the first day of Cheltenham which was a remarkable achievement.”
Connell believes O’Sullivan has made a lasting impression on the sport which will not be forgotten.
He said: “I think his legacy will be that he was an inspiration to a lot of the younger lads coming behind that somebody with the talent like his can, given the opportunities, rise to the top. I think that’s a brilliant legacy for him to have.”