Big Halloween night Friday in Hollywood … big stars, fun costumes and lots of parties.

Leonardo DiCaprio showed up to Nicolas Berggruen’s Bev Hills bash lookin’ like Andy Warhol. Drake, on the other hand, just came as himself.

And, this is interesting … with all the Facebook drama, guess who also showed up — the Winklevoss bros!!! They’re dressed as outta-this-world astronauts. And, Olivia Jade and sis, Isabella, showed up in “Black Swan” costumes, although they sure missed an opportunity, right? Rowers would have been awesome!!!

Beck showed up as a cowboy, and Simon Rex got into a “Top Gun” getup at another party deep in the Hollywood Hills. “13 Reasons Why” actor, Ross Butler, kept things honest as the sheriff.

And, now let’s go to The Reserve in Downtown L.A., where Rich the Kid took on a Michael Myers look and Austin Mahone wore the we-knew-someone-would-wear-it tracksuit.