A French mom revealed herself as the mystery do-gooder who gave ­Richard Gere food without realizing the actor was only playing the role of a homeless man.

Kindhearted tourist Karine Gombeau, 42, of Paris, had come from a bon voyage to Little Italy with her family Tuesday when she spotted a man who appeared to be a hobo sifting through the trash near Grand Central Terminal, she told The Post Saturday.

Touched by the sorry sight, Gombeau offered him leftovers from an “enormous” pizza that she, her husband and 15-year-old son had ordered at an Italian eatery, she told The Post.

“What’s in the bag?” Gere, 64, asked.

“I tried to tell him in English, but it came out half in French,” she said.

“I said, ‘Je suis désolée [I am sorry], but the pizza is cold.’ ”

Apparently, millionaire beggars can’t be choosers.

“He said, ‘Thank you so much. God bless you,’ ” Gombeau recalled.

She didn’t learn that the undercover bum was actually a famous actor until a worker at the Salisbury Hotel, where she stayed in Midtown, handed her a copy of The Post two days later. She was stunned to find a photo of herself with the star inside the paper, she said.

“It was magical . . . It’s crazy, this story. It’s unimaginable that something like this could happen,” she gushed.

“I think he’s very handsome, even at his age,” she added. “ ‘Pretty Woman’ was not my favorite movie, but I ­really loved ‘Chicago.’ ”

Gombeau, who works in the tourist industry, said it broke her heart to see homeless people in the Big Apple.

“It leaves me really sad to know we waste food and they have nothing,” she said. “It really moves me.”

Before she bumped into Gere, her husband had been shooting video of Grand Central, for fun, on his handheld camera, she said. They didn’t realize they had stumbled onto the set of Gere’s new movie, “Time Out of Mind.”

One detail, however, probably should have tipped off the tourist trio.

“People came from all over the station and told my husband to stop filming,” Gombeau said. “People came out of the subways. It was very confusing.”

The family spent four days in New York sightseeing in Times Square, at Ellis Island and in Chinatown.