The son of former Dubs' goalkeeper John O'Leary is to present the referee with the match ball for today's clash between Dublin and Galway.
Tom who's 7 will walk out on to the Croke Park pitch before the All Ireland semi-final gets underway this evening.
He was born with a heart condition called 'tertralogy of fallot' and is aiming to raise funds for the Jack and Jill Children's Foundation.
You can text 'WECARE' to 50300 to donate 4 euro to the charity.
