Celebs Dress Up for Halloween 2015

The couple dressed up as Christie Brinkley and Clark Griswold -- from the National Lampoon Vacation films -- for Halloween. "Griswold and Brinkley #HappyHalloween," Simpson Instagrammed.

The former vampire slayer went sweet, not scary for her very '80s homage to Flashdance. "Oh what a feeling .....when you are handing out candy!!!" Gellar wrote on Instagram on Oct. 31.

The fashion designer and former reality star paid tribute to the holiday classic The Nightmare Before Christmas with her spot-on Jack Skellington costume. Richie shared a pic of her impressive outfit to Instagram on Oct. 31, 2015.

The 34-year-old Victoria's Secret Angel showed quite a bit of skin dressed as a sexy devil for her Heaven and Hell Halloween party, presented by VO|CO, at 1 OAK nightclub in Los Angeles, California on Oct. 31, 2015.

The "Blank Space" singer made an adorable Olaf, from Disney's Frozen, when she performed during the stop on the American leg of her 1989 World Tour at the Raymond James Stadium in Tampa, Florida on Oct. 31, 2015.

Heidi, who ruled Halloween as the "ultimate male fantasy" Jessica Rabbit, posed with model Gigi Hadid -- who looked amazing as Olivia Newton John's character Sandy from the musical classic Grease – outside Heidi's star-studded 16th Annual Halloween Party at Lavo nightclub in New York on Oct. 31, 2015.

The Gone Girl actress donned Marge Simpson's blue beehive hairdo and iconic jaundice-like skin tone when she dressed as the famous sitcom mom for Heidi Klum’s star-studded 16th Annual Halloween Party at Lavo nightclub in New York on Oct. 31, 2015.

The Family Guy creator let his love for Star Wars shine when he dressed up in an epic Chewbacca costume for the Casamigos Tequila Halloween Party in Los Angeles on Oct. 30, 2015.

The actress and her pal nailed their Romy and Michele's High School Reunion costumes. "I invented post-its," Alba captioned the Instagram pic, quoting a classic line from the 1997 movie.

The "Roar" singer literally dropped the mic with her impressive costume.

Who says you can't wear a costume to the gym? The Jersey Shore star got in the Halloween spirit during her Saturday morning workout, getting her sweat on while sporting leopard arm warmers and ears. She even painted on whiskers and a little animal button nose, which she showed off in a selfie posted to Instagram on Oct. 31.

The Bachelorette couple went nostalgic with their costumes, dressing up as the classic duo Curious George and the Man with the Yellow Hat. "When you're Curious George for Halloween, you ask your spray tan lady to give you the Nutella glow," Bristowe joked on Instagram on Oct. 31.

The adorable couple looked cuter than ever as they paid homage to Dr. Seuss with two very different Cat in the Hat interpretations at George Clooney’s star-studded Casamigos Tequila Halloween Party in Beverly Hills on Oct. 30.

The Voice coach made for one sexy (and bloody!) cowgirl at the same Halloween bash.

The socialite-turned-DJ kept up her yearly tradition of rocking sexy costumes. For the Casmigos Halloween party on Oct. 30, Hilton opted for a viking get-up complete with a leather bustier and matching skirt.

The 51-year-old comedian opted for a furry, cuddly costume, turning up at the Beverly Hills bash in a costume he called "pizza rat."

He may be a hockey fan, but the “What Do You Mean?” singer proved he likes the hardwood as much as ice when he dressed up as Semi-Pro’s Jackie Moon on Oct. 30. Will Ferrell would be proud!

The “Focus” singer was more “moo” than “boo” when she appeared on The Ellen DeGeneres Show in the cutest cow costume ever on Oct. 30. Seriously, look at those bedazzled ears!

She may be from New Jersey, but Kelly made for the ultimate “California gurl” when she dressed up as pop star Katy Perry for the LIVE! with Kelly and Michael Halloween special on Oct. 30. Even better? Her co-star stood by her side as the ultimate meme, Left Shark!

The DWTS winner channeled the ultimate drama queen, Magenta from Rocky Horror Picture Show, as she made her way around New York City on Oct 30. While Rumer rocked a corkscrew curl wig and bold burgundy lips, she smartly skipped carrying around a gong. "It's ASTOUNDING....TIME IS FLEETING," she appropriately captioned the Instagram snap.

This Lil Kim costume may not seem like the skimpiest outfit of 2015, but as soon as the model turns around, she's definitely in the running for the prize. When Karrueche dressed up in all blue -- from the wig and furry coat to the leotard and cut-out knee-high boots -- for a Halloween party in Los Angeles on Oct. 29, both of her butt cheeks were hanging out of the ensemble. When in ... L.A.?

The 5 Seconds of Summer drummer (admittedly not playing the drums here) channeled his inner ‘80s hair band alter ego, Lucas Loxx, when the band performed at the iHeartRadio Halloween LIVE event at the iHeartRadio Theater in NYC on Oct. 29. The entire group got in on the fun, changing their Twitter handle to 5 Seconds of Sexx for the spooky holiday.

The country singer got her angel on when she hosted Life & Style Weekly’s “Eye Candy” Halloween Bash at Riviea 31 at Sofitel in Los Angeles on Oct. 29. While LeAnn didn’t get to walk the soiree’s runway with her model pals, she did have fun with the ladies she calls her “sweet girlfriends.” “Didn't make the cut 4 the runway show but I had fun letting out my inner @VictoriasSecret angel 4 a night SO much respect 4 those beautiful women!” she tweeted after the party.

The reality star showed off her new, um, assets as Disney princess Belle at Life & Style Weekly's “Eye Candy” Halloween party in L.A. on Oct. 29.

The model rocked a witch getup at Life & Style Weekly's "Eye Candy" Halloween party in L.A. on Oct. 29.

The Jersey Shore star known as Sammi Sweetheart lived up to her name when she dressed up as Disney’s sweetheart, Minnie Mouse, for the WhoSay #HereForTheBoos Halloween party at the Knickerbocker Hotel & Rooftop in New York City on Oct. 29.

The Glee star didn’t sing one audible note at the WhoSay #HereForTheBoos party in NYC on Oct. 29. How could he? Darren showed up as a mime!

The Modern Family star turned The Aristocats’ Marie into the ultimate feline ballerina for a Halloween party at Los Angeles’ Le Jardin nightclub on Oct. 29.

The talk show host and his sidekick went full force with their Halloween costumes, donning Yoda and Princess Leia costumes for the Oct. 29 episode of Jimmy Kimmel Live.

We can all admit that the British actor sort of phoned in the idea of a costume with this lion onesie (and those well-worn Adidas sneakers!), but, hey, at least he made some semblance of an effort to celebrate at the UNICEF Halloween Ball at One Mayfair in London on Oct. 29.

The English model looked every bit the part of Harley Quinn when she dressed up as the Suicide Squad character for the UNICEF Halloween Ball in London on Oct. 29. In theory, this could be paying homage to her little sister, Cara Delevingne. Kendall Jenner’s BFF will star in the upcoming movie adaption of the comic, but as Enchantress, not Harley.

The UNICEF Ambassador made the ultimate circus ringmaster at the organization’s Halloween Ball in London on Oct. 29.

The "mean girl" got catty once again when she turned up in a lacy feline costume (mask and bloody lips, included!) at The Asylum at the Cuckoo Club in London on Oct. 28.

The singer got punny with her costume, dressing up as a "Trap Queen" on Oct. 26.

Chrissy Teigen took her FABLife Halloween costume to Flavor Town, dressing up as Food Network host Guy Fieri.

The super-cute couple got their Pulp Fiction on in this Halloween Instagram.

Jenner was decked out in his hillbilly finest for a party at the Playboy Mansion on Oct. 24.

Hough looked fang-tastic in his getup for Dancing With the Stars' Halloween episode.

"I want to suck your blood !!!!" Hough captioned the Instagram pic, adding the hashtags, "#dwts #halloween #teamcrikey."

The Arrow star always goes all out for Halloween and this year was no exception! Haynes shared this pic of himself done up as Ursula the Sea Witch from The Little Mermaid, with the caption "Poor unfortunate souls."

Beyonce and her friends went all out for singer Ciara's superhero-themed birthday party on Oct. 24. Check out La La Anthony as Wonder Woman, Ciara and Kelly Rowland as Catwoman, and Queen Bey herself as the icy-eyed Storm!

Model Lily Collins also showed off her super side at Ciara's hero-themed birthday bash.

The Dancing With the Stars pro and his girlfriend rocked the red carpet at Maxim's Oct. 24 Halloween party as Kurt Cobain and Courtney Love.

The singer and Scream Queens star showed up as the Hamburgler at the Maxim Halloween party on Oct. 24.

The Scream Queens star turned the red carpet into a catwalk at Maxim Magazine's Halloween party in Beverly Hills, California on Oct. 24. 

The DWTS brothers strutted their stuff at the Maxim Halloween party on Oct. 24.

Singer Aubrey O'Day rocked a Cruella de Vil costume at Maxim's Halloween party on Oct. 24.

The Iron Man star donned this Tigger getup to brighten the day of a young fan with cystic fibrosis. Downey then did one better, inviting the fan to join him at the Captain America: Civil War premiere!

Conrad showed off her inner "party animal" for a DIY costume suggestions on her website.

No six-pack abs here! The Magic Mike XXL star rocked this paunchy (and kind of weird) Winnie the Pooh costume, and shared the pic on Instagram on Oct. 17, 2015. Channing explained the outfit in the photo caption, writing, "Pretty sure I terrified all the children at our daughter's Halloween carnival today. Btw- I'm pooh bear in case anyone can't tell."