 He arrived on the inter-county scene at the age of twenty-three when he first linked up with the Offaly junior team.He made his senior debut for Dublin during the 1925 championship before becoming a dual player with Cork's senior teams the following year.O'Regan immediately became a regular in the inter-county scene and won four All-Ireland medals, four Munster medals and two National Hurling League medals as well as a Munster football medal.