Celine Dion Waves To Serenading Fans After Olympics Performance Rehearsals

Celine Dion returned to her hotel after a marathon day of Olympic rehearsals in Paris to find a surprise concert of her own -- courtesy of her fans singing and cheering for her one day before her grand stage comeback.

Check out the vid ... the singer had her hand over her heart as she took in the unexpected serenade before heading indoors in the early hours of Thursday.

Celine was rocking a stunning black dress with her hair pulled back in a bun, showing off that big, dazzling smile as she watched the crowd do her thing.

As we reported, Celine's just a day away from taking the stage with Lady Gaga for the opening ceremony of the Olympics -- where they're both set to perform Édith Piaf 's classic "La Vie en Rose."

PARIS GEARS UP FOR OLYMPICS GAMES

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TMZ broke the news Celine’s gearing up to perform this Friday, pulling in a staggering $2 million for just one song for her first performance since she revealed her Stiff-Person Syndrome diagnosis in 2022.

CELINE DION PERFORMANCE PHOTOS

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It'll definitely be a super empowering moment, and Celine shows no signs of stopping ... TMZ broke the story she’s making a grand return to Las Vegas to launch a new residency.

Sources with direct knowledge of the deal tell TMZ ... Celine's in the final stages of negotiating a new residency at Resorts World, which is supposed to start in late 2024 or early 2025. One source said, "It's basically a done deal. She's doing it."

Vegas, here she comes ... again!