The 2023 US Open Championships kicked off in New York City on August 28 — with several celebrities in attendance.

The first night of the tournament included a performance from Sara Bareilles to honor Billie Jean King and the 50th anniversary of equal prize money.

“There is nobody like her. She has walked the walk in the name of equality and justice since the beginning of her career,” Bareilles captioned an Instagram photo of her posing with King and music director Nadia Digiallonardo. “We celebrate 50 years since @billejeanking changed the game and the way women were seen and valued by securing equal prize money!! Her relentless pursuit forged a movement that changed an industry and the world, and to know her is to know one of the most bright, curious, interested, charismatic, intelligent, passionate people on earth.”

Keep scrolling to see every star that attended the 2023 US Open so far:

The Olympian showed up with her boyfriend, Diego Osorio, on August 28. Vonn posted photographs from the event via her Instagram Stories, including a snap of her and former tennis champion Chris Evert. “The epitome of strength and kindness,” she captioned the pic of her hugging Evert.

“Here’s to @BillieJeanKing and all the changemakers who broke barriers and opened doors for future generations — and to the @USOpen for raising the bar not just for the tennis world, but for the entire world 🎾,” Michelle wrote via Instagram alongside a snippet from her speech at the opening night of the US Open on August 28.

The Baldwins dressed up for the US Open on August 28 with Hilaria sporting a bright pink top with a black skirt while Alec opted for a navy suit.

The fashion designer was spotted sitting next to Wintour. “When you match the opening night carpet….. 🎾💙,” Wang captioned an Instagram photo of her outfit on August 28 which consisted of a white long sleeve top and blue skirt.

Couric and her husband, John Molner, had a date night at the first round of the Grand Slam on August 28. Couric wore a floral dress while her husband wore a checkered light blue sports coat.

Bareilles performed her song “Brave” in honor of King on August 28. “She is the gold standard of human,” the singer captioned a photo of her and King via her Instagram Story. 

The couple — who tied the knot in 2015 — shared a selfie via their Instagram Story on August 28 from the event alongside a video of Novak Djokovic hitting the ball.

The playwright shared a selfie of him to his Instagram Story of him and his wife, Vanessa Nadal, while enjoying the tennis match on August 28.

“The suit game was red hot this week 💥💥💥,” the tennis star captioned photos of her red pantsuit via Instagram on August 28.