The son of a cattle farmer and a publican, O'Regan was born in March 1982 in Youghal, County Cork, and gained experience in pony racing and drag hunting before becoming a jockey.
[4] O'Regan gained his first Grade 1 win on Offshore Account, trained by Charlie Swan, in the 2007 Hanover Quay Champion Novice Chase at Punchestown.
At the 2008 Cheltenham Festival he rode two Grade 1 winners for Johnson, Tidal Bay in the Arkle Challenge Trophy and Inglis Drever in the Stayers' Hurdle.
[5] In November 2008 O'Regan rode Black Appalachi to victory over Grand National fences in the Becher Chase at Aintree for Dessie Hughes.
The pair achieved success with Tully East, trained by Alan Fleming, in the Close Brothers Novice Handicap Chase at the 2017 Cheltenham Festival.