Jennifer, 50, struck a sexy pose during her time in the coastal town on the French Riviera.
She sizzled in a white bathing suit with "forever young" written in gold in the middle.
The Bronx native struggled to stay covered in the revealing outfit.
Fans didn't seem to mind. "Can you please tell us your secret to the fountain of youth," one of them wrote.
The mother-of-two suffered a wardrobe malfunction on the set of her upcoming movie Hustlers in May 2019 when she accidentally flashed her underwear while wearing a super short skirt.
Jennifer and her fiancé Alex Rodriguez were spotted heading to Magic Johnson's 60th birthday party in St. Tropez on Monday, September 2.
The global icon sported a belly baring white top with a black and white skirt for the former NBA star's big celebration.
What are your thoughts on J. Lo's risque ensemble in St. Tropez? Sound off in the comments!