Halloween has officially hit Hollywood — with massive parties to kick-off the holiday — including star-studded events held by Paris Hilton and Dan Bilzerian.
Paris' party was held at a massive estate in Beverly Hills … guests included Heidi Klum and her hubby, Kelly Osbourne, Paris Jackson, Jason Derulo and Ryan Phillipe. Paris was decked out in a super-hero worthy costume.
Blizerian held his bash at a mansion in Bel Air with celeb buddy Diplo in attendance. The party even featured a neon haunted house for brave guests to walk through.
There are still plenty more parties ahead — with the Cindy Crawford and Rande Gerber's Casamigos event Friday — so keep an eye out for the best dressed celebs.