He rode for a couple of seasons as an amateur for stables in Yorkshire, his first winner being Fair Bavard for Harry Wharton at Southwell on 29 March 1986.
[3][4] Osborne's most successful season was 1996-97 when he rode 131 winners and came second in the British jump racing Champion Jockey table, behind Tony McCoy.
In November 1997 Osborne rode 33/1 outsider Senor El Betrutti to victory in the Murphy's Gold Cup at Cheltenham and 24 hours later fractured his left wrist in a fall at the same racecourse.
He won the 2014 UAE Derby at Meydan Racecourse in Dubai and later that year came second in the Breeders' Cup Classic on the dirt track at Santa Anita Park, beaten by only a nose.
[9] In 2002 Osborne was fined £4,000 by the Jockey Club for bringing racing into disrepute after he was caught on camera making unguarded remarks on the BBC Kenyon Confronts programme.
[6] When racing was suspended due to the COVID-19 pandemic in the United Kingdom, Osborne filmed homemade musical productions in his yard which proved popular on Twitter.
[11][12] Upon being reported to West Berkshire Council, Osborne applied for retrospective planning permission after the illegitimate construction of a horse gallop was found.
[14] The retrospective application was approved (subject to certain mitigating conditions) despite the recommendation of refusal from the Western Area Planning Committee.
[16] In June 2021 Osborne contacted police after his daughter was the subject of threats on social media; this led to a wider debate about online abuse of racing participants.