Cormac Costello is a Gaelic football forward for Dublin, with whom he has won an All-Ireland Senior Football Championship medal as a panellist and a National Football League medal twice. He plays his club football for Whitehall Colmcille.Costello won an All-Ireland Minor Football Championship in 2012, then an All-Ireland Under 21 Football Championship in May 2014. In 2014, he was a sub in the quarter-final victory over Laois in the Leinster Senior Championship. He scored three points in the game. During the semi-final victory over Wexford he was a sub again and he scored 1-05. He won a Leinster Senior Championship against Meath in 2014. He was a sub and scored one point in the game. In the All-Ireland quarter-final Costello was a sub again and managed one point in a one-sided game against Monaghan. He was anonymous against Donegal and was hauled off the field as Dublin crashed out in the semi-final.