"It's a marvelous surprise and one I was not expecting," French radio network RTL quoted Bardot, an animal-rights activist , former singer and fashion model, as saying.
Bardot, 78, had said for weeks she was worried sick since 2-year-old Rontonton disappeared from the exclusive Riviera resort of Saint-Tropez, where Bardot lives. The cat ran away March 26 while gardeners were trimming bushes on Bardot's property.
The disappearance sparked a cat hunt that brought the offbeat Canal Plus TV news show "Le Petit Journal" to help drum up publicity to help find Rontonton.
Local newspaper Var Matin also launched an appeal that brought some 200 calls from people saying they saw the cat.
"My pain is terrible. I cannot sleep," Bardot was quoted by the French version of The Local online news portal as saying at the time.
Rontonton was found by a couple on a road outside St. Tropez. The couple's grandson apparently recognized the cat from the appeal photo, The Local said.
Bardot gave the couple 600 euros -- about $680 -- which she had pledged for Rontonton's safe return.