And last night's soiree didn't disappoint with Nicole Scherzinger, Millie Manderson (nee Mackintosh), Holly Willoughby and Dermot O'Leary among the stars donning their spookiest (or sexiest) outfits to party the night away.
X Factor judge Nicole turned heads in a skintight leather Catwoman outfit, complete with cute cat ears and her trademark bouncy hair. Being a superhero has never looked better!
She clearly had a good night mingling with pals including Kate Moss, who honoured Mexico's Day Of The Dead with her outfit and, at one point, bizarrely tried to put a pig's snout on Nicole. Thanks to Jonathan Ross for sharing that photo! As he put it: "I am about to post one of the greatest pics on Twitter ever ...."
Newlywed former Made In Chelsea star Millie also went for a sexy rather than scary costume, invoking her inner Morticia from The Addams Family in a racy floor-length leather dress. Husband Professor Green channelled the dapper Gomez.
Elsewhere, This Morning presenter Holly Willoughby impressed with her cute platinum blonde bob and vampy black lips, while
Other guests included Jimmy Carr, who arrived as Steve Martin's creepy dentist character from Little Shop Of Horrors and a zombie Simon Pegg.
Host Jonathan Ross decided to dress as David Bowie's punk rock King Jareth from iconic movie The Labrinth. Love the hair!
Check out fab costumes from Hugh Laurie, Jack Whitehall, Jonathan Rhys Meyers and more: