Coco
"Harley Quinn at your service," the model wrote. "Want to be my #puddin?"
Tyler Hubbard
"@elviecreations nailed the Gus Gus & Jaq costumes!!" Hayley Hubbard wrote on Instagram. "We searched high and low on Etsy and scoured the internet and every local seamstress and Laura came through with the winning costumes for Luca and Altas."
Allyson Felix
"Do you prefer fashion victim or ensembly challenged??" the Olympian wrote on Instagram. "#clueless #asif #cluelesscostume #happyhalloween."
Alessia Cara
The singer channels the late Amy Winehouse.
Sophie Turner & Joe Jonas
The couple pays tribute to the Lizzie McGuire Movie while attending the Casamigos Halloween party.
Eniko & Kevin Hart
The group reenacts Michael Jackson's "Remember the Time" music video.
Chris Hemsworth & Elsa Pataky
Bloody adorable.
Alessandra Ambrosio
We spy an Ice Princess at Darren Dzienciol's CARN*EVIL Halloween party presented by DECADA!
Nina Dobrev, Shaun White & Adam DeVine
The three pay tribute to The Queen's Gambit.
Doja Cat
Someone looks like The Powerpuff Girls' Sara Bellum at the CARN*EVIL Halloween party powered by Geojam.
Sarah Michelle Gellar & Freddie Prinze Jr.
"Nobody puts baby in the corner," the actress joked on Instagram. "#happyhalloween from Baby Houseman and Johnny Castle #dirtydancing #loverboy."
Meagan Good
The star rocks a sexy style at the CARN*EVIL Halloween party.
Trevor Noah
The comedian does his best portayol of The Weekend.
Victoria Justice
Spooky! The actress steps out for Darren Dzienciol's CARN*EVIL Halloween party.
Paris Hilton
The bride-to-be makes one sexy Cinderella.
Ryan Phillippe
We spot a pirate exiting Darren Dzienciol's CARN*EVIL Halloween party, featuring catering by Butter Bun.
Jade Thirlwall
The Little Mix star channeled Marge Simpson at Maya Jama's annual Halloween party.
Zooey Deschanel
"Happy Halloween from me & my pet spider. Do you think I can get away with making this hat an every-day accessory?" the actress shared, to which her boyfriend Jonathan Scott replied, "Oh I think you can get away with just about anything."
Bebe Rexha
The pop star recreated Anna Nicole Smith's infamous wedding for Halloween, writing on Instagram, "Icon Anna Nicole Smith getting married to J. Howard Marshall II. Happy Halloween Eve."
Reese Witherspoon
The actress quipped, "There's something wrong with the birds!"
Maya Jama
The host herself went above and beyond with her costume to celebrate her annual fête in London.
Antoni Porowski
The Queer Eye star was in good spirits as he attended Bette Midler's New York Restoration Project's Annual Hulaween Gala.
Vanessa Morgan
The Riverdale star got into a Matrix mood, writing on Instagram, "You have to understand, most of these people are not ready to be unplugged. And many of them are so inert, so hopelessly dependent on the system that they will fight to protect it."
Miranda Kerr & Evan Spiegel
"Ready for takeoff #happyhalloween," the supermodel shared.