Born in Bennettsbridge, County Kilkenny, McGarry first played competitive hurling whilst at school in Kilkenny CBS. He arrived on the inter-county scene at the age of twenty-one when he first linked up with the Kilkenny junior team. He joined the senior team for the 1997 championship. McGarry went on to play a key part for Kilkenny for over a decade, and won five All-Ireland medals, seven Leinster medals and three National Hurling League medals. He was an All-Ireland runner-up on two occasions.