O'Mahony first came to Gaelic football prominence at juvenile and underage levels with the Clonakilty club in West Cork.
He made his senior club debut in 1979 and was part of the Clonakilty teams that lost county finals in 1983 and 1985.
O'Mahony was straight out of the minor grade when he earned selection with the Cork senior football team.
O'Mahony's other honours include two Munster Championship medals and a National Football League title.
[3] Shortly after his retirement from club activity, O'Mahony took over as manager of the Clonakilty senior team.