Shawn Johnson, retired U.S. Olympic gymnast.
Jordyn Weiber, U.S. gymnast and member of the Gold medal-winning US Women's Gymnastics teams at the 2011 World Championships and the 2012 Summer Olympics.
Tyler Clary, swimmer and Olympic gold medalist
Pat McAfee, outspoken punter for the Colts. (Getty)
Mario Andretti, racing legend
Michael Pena, who will serve as the celebrity starter for the race, is a film and television actor, and musician, best known for his roles in "Crash," "World Trade Center" and "End of Watch." He lends his voice to the upcoming "Turbo."
Windell Middlebrooks, film and television actor best known for his Miller High Life beer commericials.
Florence Henderson, actress and Indianapolis 500 staple
Eddie Money, rock star with hits including "Two Tickets to Paradise," "Walk on Water," "Take Me Home Tonight."
Foreigner, British-American rock band with hits including "I Want to Know What Love is," "Double Vision," "Hot Blooded," "Feels Like the First Time," "Cold As Ice" and "Juke Box Hero"
Jim Nabors, actor and Indianapolis 500 staple