Leo DeCaprio got a taste of what’s goin’ down in a year, because his 49th birthday party was off the hook!

The party went down at an event space in Bev Hills and the guest list is exhausting to type … Lady Gaga, Salma Hayek, Snoop Dogg, Irmelin Indenbirken, Soleil Moon Frye, Scott Eastwood, Casey Affleck and Caylee Cowan, Kate Beckinsale, Zoe Saldaña and Marco Perego, Jordan Masterson, Luka Sabbat, 2 Chainz, Rita Ora and Taika Waititi, Beck, Chris Rock, Corey Gamble, Emile Hersch and Lukas Haas.

Kate Beckinsale was a glittery standout with ginormous diamonds caressing her waist.

Here’s who we didn’t get … the ever-elusive Leo, who evaded paparazzi in a pretty spectacular way — given it was his party!

We also don’t know if his current GF, Vittoria Ceretti was there, but it’s a good bet since we didn’t see either of the 2 they both came together.

BTW … Salma Hayek had a busy night … she arrived after attending the Baby2Baby Gala — a charity for underprivileged kids — where she received the Giving Tree Award.