Monaghan first played hurling at club level with Kildorrery as a 15-year-old in 1959. His career with the team lasted until 1988, by which stage he had won seven North Cork JHC titles. Monaghan also lined out as a Gaelic footballer with the nearby Mitchelstown club. Beginning with a Cork MFC title in 1960, he also won a Cork IFC title in 1965. Monaghan's club performances also earned his selection to the Avondhu divisional team. He lined out in goal when the team beat University College Cork to win the Cork SHC title in 1966.
