He was educated locally and later worked as a bank official.
At club level Kirwan first played competitive football with Lismore Blackwater Ramblers, with whom he won a county senior championship medal in 1899.
Kirwan later enjoyed championship success with the Camblin Rovers club in Wexford before ending his club career with the Castleisland Desmonds club in County Kerry.
Kirwan first played on the inter-county scene as a member of the Waterford senior team that was defeated by Dublin in the 1898 All-Ireland final.
He later lined out with Wexford before making his debut with the Kerry senior team in 1902.
Kirwan went on to win back-to-back All-Ireland medals with Kerry in 1903 and 1904.