Serena Williams Flexes In Hollywood After Wimbledon Loss, I Ain't Sad!

The Wimbledon L clearly ain't affecting Serena Williams ... the tennis legend was out partying in Hollywood on Thursday -- and she looked GREAT!!!!

The 37-year-old superstar hit up Sunset Room for the Sports Illustrated Fashionable 50 party -- you know, the one where they honor the 50 hottest athletes in the world -- and Serena killed it.

Obviously, some thought a rough loss to Simona Halep on Saturday might hamper her style ... but, clearly, there ain't no hangover here!!

Other celebs crushed it too ... Michelle Wie, Errol Spence Jr., Ben Simmons, DeAndre Jordan and Chloe Kim all rocked fancy duds.

Also, NBA stud Kelly Oubre Jr. showed up in this.

Lindsey Vonn and her hockey-playing BF, P.K. Subban, were also there -- and they've sure been getting close lately.