The talk show host kicked off her celebrations at The Lot Studios in West Hollywood, California, over the weekend, with a slew of A-listers by her side. Interestingly enough, the party brought together a few famous exes, who arrived with their new significant others.
Gwyneth Paltrow, chic in a red jacket, black pants and stilettos, appeared to be having a blast at the soiree, packing on the PDA with her fiancé, Brad Falchuk.
Paltrow's ex-husband, Chris Martin (whom she shares two children with), was also there, stepping out and holding hands with his girlfriend, 50 Shades Freed star Dakota Johnson.
At one point, the lovebirds were spotted chatting with Drew Barrymore, who arrived with a mystery man.
The Santa Clarita Diet star wasn't the only one who showed up with a potential new love interest, however. Jennifer Lawrence (who also briefly dated Martin) turned heads in a black dress with a slit, but it was hard not to notice the well-dressed man by her side.
Meanwhile, Leonardo DiCaprio, seemingly trying to keep a low profile in a baseball cap, slyly made his way into the party with his model girlfriend, Camila Morrone.
Jennifer Aniston also seemed to be in good spirits on Saturday, laughing and smiling as she ran into her pal, Pharrell Williams.
Others in attendance included Kris Jenner, Kim Kardashian West, Kanye West, Chrissy Teigen, John Legend, Amy Schumer, Jennifer Lopez, Olivia Munn, Sean "Diddy" Combs, French Montana, Reese Witherspoon and David Spade.