At club level he played with Éire Óg and was a two-time All-Ireland Championship winner with the Kilkenny senior hurling team.
O'Brien began his playing career at club level with Éire Óg, and helped them to their four county senior championship successes in 1939, 1944, 1945 and 1947.
He played at minor level with Kilkenny in 1938 and again in 1939 when the team lost out to Cork in the All-Ireland final.
O'Brien broke onto the Kilkenny senior team in 1946, winning a Leinster Championship in his debut year, and was a substitute on the 1947 All-Ireland Championship-winning side.
He was an active trade unionist and was chairman of the Kilkenny city branch of the Labour Party for nearly 20 years.