Williams' husband and their daughter have been in her box to watch both of her matches at the US Open so far.

Williams and Ohanian, a co-founder of Reddit, married in 2017. Williams gave birth to Olympia later that year.

Venus, who was knocked out of the women's singles draw in the first round on Tuesday, watched her sister beat World No. 2 Anett Kontaveit at Arthur Ashe Stadium on Wednesday night.

The two sisters played together in the women's doubles on Thursday, where they lost to the Czech duo Linda Nosková and Lucie Hradecká in the first round.

Price is Serena and Venus' mother.

She coached the pair alongside their father and her former husband, Richard Williams, as youngsters.

Price and Williams divorced in 2002, after which she reverted to using her maiden name. 

Woods was in Williams' box alongside his girlfriend, Erica Herman, to watch her beat Kontaveit on Wednesday.

Williams has a close relationship with the golfer and told reporters that he was "one of the reasons" she is playing at Flushing Meadows this year.

"We talked a lot, he was really trying to get me motivated," she said of Woods. 

"When you can rely on someone like that, I mean, my goodness, he's Tiger Woods, it was really helpful to get clarity."

Wintour, the editor of Vogue magazine, has been in Williams' box for both of her matches so far.

Williams announced that she would be "evolving away" from tennis after the US Open via an emotional letter published in Wintour's magazine last month.

Stubbs, a multiple Grand Slam doubles champion, has been helping coach both Serena and Venus at the US Open. 

Serena's coach Eric Hechtman; her agent, Jill Smoller; and Jamere Jenkins, one of her hitting partners have also been guests in the box. 

Zendaya, an American actress and musician, is starring in a tennis movie named "Challengers" next year.

Models Gigi and Bella Hadid were at Williams' match on Wednesday and were very vocal in their support for the American tennis star.

According to Grazia, Gigi wore a gold "S" pin for Serena on her red jumpsuit.

Ahead of Williams' first-round match this year, movie director Lee shared a special message for the 40-year-old with the US Open's Twitter account.

"I think of you as my little sister," Lee said in a video. "Congratulations on all you've done. You're definitely one of the GOATs.

"I want to give love to your parents and your siblings, because they've helped you, too. Spreading love is the Brooklyn way."

British singer Seal, the ex-husband of model Heidi Klum, was in the stands to watch Williams on Wednesday.

Before the match, he was pictured hugging his and Klum's eldest daughter, Leni Klum, 18.

Warwick was mistaken by a commentator for Motown legend Gladys Knight as she watched Williams on Wednesday.

The 81-year-old appeared to find the mistake funny, tweeting after the match: "Hi, I'm Gladys Knight, and instead of taking that midnight train to Georgia, I won't walk on by but will say a little prayer for you."