Kielty (38) replaces Des Cahill, who has moved to The Sunday Game highlights programme, on the first episode of the new look GAA programme.
The Road To Croker also has a new Friday-night time slot at 7pm on RTE 2, where it will herald the beginning of every GAA weekend.
Big-name interviews, nostalgia and grassroots issues will all be filtered through "a uniquely irreverent perspective" according to RTE.
Kielty, whose Celebrity Bainisteoir team beat Marty Whelan's in the hit series, returns to Dundrum, Co Down, where he once played football.
There, he is "still Paddy Kielty who played football for Dundrum, who goes to the pub and buys my round", he says.
In The Road to Croker, he talks about how his first stand up performances were about the GAA. He claims the phrase "who does yer man think he is" was coined by the Association.
Kielty was pretty serious about his football, winning an All-Ireland medal with the Down minor team in 1987.
Earlier this year, his home club named their pitch after his father, businessman Jack Kielty, who was murdered by Loyalist paramilitary group the Ulster Freedom Fighters.
Also in the first programme, rival net minders Clinton Hennessy of Waterford and Brendan Cummins of Tipperary explain the pressures on a hurling goalie ahead of their clash in the Munster Hurling Final and tell how they came to be the guardians of the net.
The programme also asks why it has been 10 years since a Leinster team won an All-Ireland football title?
With Leinster football going through a serious drought, Dr Pat O'Neill diagnoses the problem, while Meath tough guy Colm Coyle prescribes the cure.
Des Cahill moved to the Sunday Game programme hotseat in May as its new presenter, where he chairs the show that features highlights of all the championship matches, analysis and discussion.