John Isner and Bernard Tomic of Australia have became wild cards as part of an agreement between the French, U.S. and Australian federations. The French Open begins on May 24.
American Lauren Embree and Australian Olivia Rogowska will join several French wild cards.
The 30-year-old Gaudio, ranked No. 395 after a series of injuries, has not won a title in four years. He captured the 2004 title at Roland Garros over Guillermo Coria.
It's the second year in a row that French Open organizers have given a wild card to a former champion. Last year, it was three-time winner Gustavo Kuerten.