Five Royal Ascot winners, an Oaks double, an extraordinary St Leger success: inside Joseph O'Brien's watershed Flat season

Trainer Joseph O'Brien has enjoyed a landmark 2026 Flat season, saddling 127 Flat winners in Ireland, five Royal Ascot winners, an Oaks double, and a notable St Leger success, far eclipsing his previous best prize-money figures. His performances have elevated him from the top tier into the elite of global horse racing, with analysts suggesting he could challenge the Irish Flat winners record of 154 set by his father Aidan O'Brien in 2018. He also has ten horses capable of running in the Melbourne Cup, underscoring his growing international reach.