The late Hollywood legend set up The Hole in the Wall Gang Camp organisation in 1988 to provide a summer camp experience for sick kids.
Cooper spent a week at the site in Connecticut as a counsellor working with the children, and now he has been given a more permanent role.
He says, "When I spent a week at The Hole in the Wall Gang Camp as a counsellor, I was amazed at how the spirit of Camp is able to help kids facing so much escape their illness, make fast friends and remember what being a kid is all about. I am excited to be joining The Hole in the Wall Gang Camp's Board of Directors..."
Newman, who named the charity after the gang in his film Butch Cassidy and the Sundance Kid, died in 2008.