Rihanna
The singer wore this outfit to Rita Ora's Halloween party in London.
Jessica Biel, Silas Timberlake & Justin Timberlake
"This Halloween was one hell of a block party!" the actress joked. "Happy Halloween from our LEGO family to yours."
Kris Jenner
The Keeping Up With the Kardashians star called designer Laurel DeWitt "truly so talented" for transforming her "into my version of Cleopatra!!! You made it so glamorous!!!!"
Tom Kaulitz & Heidi Klum
As ogres, the couple was practically unrecognizable!
Jaden Smith
Halloween may have passed, but the musician is still pumped to experience Universal Studios Hollywood's Halloween Horror Nights.
Megan Fox
The actress cast a spell on her muggle children.
Lupita Nyong'o
As if the actress would be any other Clueless character than Dionne!
Margot Robbie & Cara Delevingne
The Hollywood besties attend the Queen Mary's Dark Harbor in Long Beach, Calif., for a spooktacular Halloween celebration.
Joe Manganiello, Manolo Gonazalez Vergara & Sofia Vergara
The trio takes a "family portrait" before their fright fest begins.
Pink & Carey Hart
"Screw it," the singer said of her family's Greatest Showman costumes. "I love Halloween so much."
Joe Jonas & Sophie Turner
They're creepy and they're kooky—especially as the Addams family's Gomez and Patricia!
Lala Kent
"Shout out to everyone who got a costume and followed through with putting it on and looking epic," said the Vanderpump Rules star, who wore a mature Mickey Mouse costume. "I bought a costume and only got as far as trying it on to show Rand. Then we took the babies trick-or-treating and by 8:30 we were home watching Food Network."
Kourtney Kardashian
Quoting Ariana Grande, the E! star captioned her Instagram shot, "God is a woman."
Adrienne Bailon
It's date night for The Real co-host and Israel Houghton who celebrate Halloween at Nights of the Jack in Calabasas, Calif.
Joey Fatone
The *NSYNC member deserves rave reviews for his costume at Podwall Entertainment's 9th Annual Halloween Party presented by Maker's Mark at The Peppermint Club.
Reese Witherspoon & Jim Toth
With their sons by their side, the ghoulish duo wished everyone a "spooky night."
Olivia Munn
The actress got into character as comedienne Ali Wong.
Jessica Simpson & Eric Johnson
Danny DeVito and Arnold Schwarzenegger should be proud of their Twins costumes.
Mindy Kaling
"Happy Halloween from this bottle of mustard and her little lion," Kaling wrote.
Mariska Hargitay & Peter Hermann
"Couples who avenge together..." the actress joked.
La La Anthony
The Power actress gets into character as Marvel's Silver Sable.
Neil Patrick Harris & David Burtka
"After hours of trick-or-treating, the only thing to do is get dressed in another costume and go to @heidiklum's Halloween Bash," said Burtka, who dressed as a Princess Bride character with his husband. "Great good times."
Kylie Jenner
"Don't you wanna Fanta?"
Vanessa Lachey
"Daddy's on tour so Mama tried to get it together," the host wrote. "The fun of Halloween has a completely different meaning now, haha! We miss you Mr. Incredible! (Camden asked why my costume was so tight. Good question Buddy, good question!...)"