As our photo shows John joined fitness guru to the stars Pat Henry for some last minute training for the walk.
The event is taking place in 14 locations across the country -- and more than 20,000 people have applied for sponsorship cards.
The Dublin Walk of Dreams will leave Fitzwilliam Street near Merrion Square at 3pm and the walkers will be welcomed to the home of Irish football -- the Aviva Stadium.
Fresh from their Euro 2012 encounter with Macedonia the night before, Irish senior players will be there to add their encouragement to the next generation of footballers.
For further information, visit www.johngilesfoundation.com.