The 26-year-old Frenchman, who reached the last four in 2008, has dropped down the rankings to 119 from a high of seven in 2011.
Compatriot Virginie Razzano, who stunned current World No 1 Serena Williams in the opening round last year, has also been handed an automatic entry.
The French Open takes place from May 26 to June 9.
Wildcards:
Men: Gael Monfils, Marc Gicquel, Nicolas Mahut, Adrian Mannarino, Lucas Pouille, Florent Serra (all France), Alex Kuznetsov (USA), John Millman (Australia)
Women: Virginie Razzano, Aravane Rezai, Claire Feuerstein, Stephanie Foretz-Gacon, Caroline Garcia, Irena Pavlovic (all France), Ashleigh Barty (Australia), Shelby Rogers (USA).