Twomey first played Gaelic football as a student at the De La Salle College in Macroom, while also lining out at underage levels with the Macroom club. After winning a Cork MFC title in 1986, he progressed to adult level. Twomey was the team's top scorer when Macroom won the Cork IFC title in 1990. He also earned inclusion on the Muskerry divisional team.
