The pair are reportedly working on their marriage following allegations of cheating.
Portman, who was in attendance at Parc des Princes Saturday to see PSG take on Clermont Foot 63, rocked a plaid blazer over a white shirt and blue jeans. The Thor: Love and Thunder actress accessorized the look with a bold, red lip and a pair of cat-eye sunglasses.
In addition to cheering on PSG, Portman, who helped co-found the Los Angeles National Women's Soccer League team, Angel City FC, was seen chatting with tennis star, Novak Djokovic, who was seated a few rows behind her.
Like many of the fans in the stands, Portman was also captured taking photos of the match, which despite a loss from PSG, ended with the famed football club earning the Ligue 1 title for the 11th time.
The smiling photos mark the first public appearance for Portman since French outlet Voici alleged that Millepied had been having an affair with a 25-year-old woman.
A source told People that the alleged affair was "short-lived and it is over," adding that the Oscar winner and her dancer husband have been privately working through their marital struggles despite the allegations.
"He knows he made an enormous mistake and he is doing all he can to get Natalie to forgive him and keep their family together," the source told the outlet. "Natalie is incredibly private and has no intention of playing this out in the media. Her biggest priority is protecting her children and their privacy."
ET has reached out to Portman's rep for comment.
Portman and Millepied first met on the set of Black Swan, in which Portman starred and Millepied choreographed and appeared. They collaborated again on her 2018 film, Vox Lux, in which Portman played a troubled pop star. In 2011, they welcomed their first child together, son Aleph, followed by daughter Amalia in 2017.
The couple wed on Aug. 4, 2012. They celebrated their 10-year wedding anniversary in August 2022. Portman and Millepied were recently seen together in the City of Lights, where the actress joined the numerous celebrities in town for Beyoncé's Paris stop on her Renaissance World Tour.
Photographers caught the parents of two on May 29, enjoying dinner and kissing after a screening of her film with Julianne Moore, May December, for the closing evening of Chimeres Americaines at Centre Pompidou.