Kylie Jenner & Stassi Karanikolaou as Madonna & Britney Spears
The Kylie Cosmetics founder and her BFF got into spirit of Halloween in 2019 by dressing up as Madonna and Britney Spears from their iconic 2003 MTV VMAs.
Lisa Rinna as Jennifer Lopez
Rinna from the Block! The Real Housewives of Beverly Hills star channeled the one and only Jennifer Lopez for the 2019 Casamigos party.
Lisa Rinna as Erika Jayne
The Real Housewives star dressed up as her pal and co-star for Halloween in 2018. In response to Lisa's costume, Erika commented, "I LOVE YOU!! AMAZING!!"
Halsey & Evan Peters as Sonny & Cher
I got you babe! Making their red carpet debut as a couple at the AHS 100th Episode celebration in 2019, the singer and the actor proved there ain't no hill or mountain we can't climb. Alas, much like the former power couple, the duo called it quits months later.
Nina Dobrev & Pal as Gigi Hadid & Fashion Week Crasher
A major pop culture moment from 2019! The Vampire Diaries alum found the humor with her Halloween costume as she and gal pal recreated the Chanel Fashion Week Show prankster. You know, where Gigi Hadid totally stopped a crasher from ruining the runway.
Nina Dobrev as Billie Eilish
Nina was a "bad guy" when dressed up as singer Billie Eilish for the Casamigos party in 2019.
Tana Mongeau & Jake Paul as Britney Spears & Justin Timberlake
The former YouTube couple channeled one of pop's most famous couples in their iconic head-to-toe denim looks in 2019.
Olivia Munn as Ali Wong
"HAPPY HALLOWEEN!!! #AliWong #HardKnockWife #halloween," Olivia captioned her Instagram post showing off her 2019 costume. She later thanked Ali for "helping me get your exact same dress."
Nick Viall as Peter Weber
Nick Viall deserved a final rose for his spot on Halloween costume. "Just a Pilot on a flight for love," the former Bachelor star cheekily captioned a photo of his 2019 costume. "Will probably crash into a windmill tonight."
Jessica Simpson & Eric Johnson as Danny DeVito & Arnold Schwarzenegger
Jessica, is that you?! The couple totally nailed their 2018 costumes, paying homage to the 1988 comedy Twins.
Mel B as Victoria Beckham
The Spice Girls star dressed up as her former bandmate "not going on tour" alongside her pal, who wore a David Beckham costume, at a party in 2018.
"Yesssss @heidiklum yippppeee first year coming to her party wow wow wow what an amazing Halloween party right now,seriously it's on fire haha me and @gary_90210 never laughed soooo much #livingmybestlife #ny #bellylaughs @lavony was lit," she captioned a photo of their costumes on Instagram.
Kourtney Kardashian as Ariana Grande
Kourtney Kardashian dressed up as family friend Ariana Grande for Halloween in 2019. And the "God Is a Woman" songstress loved it, commenting a series of hearts on Kourtney's Instagram photo.
Harry Styles as Elton John
The "Watermelon Sugar" singer dressed up in a sparkling Dodgers uniform and sunglasses, similar to the ensemble Elton John wore in 1975 during his performance at Dodgers Stadium in Los Angeles, while attending the 2018 Casamigos Halloween party.
"Now that's what I call a Halloween costume @harrystyles," Elton wrote on Instagram along with photos of Harry in the costume.
Harry and Elton have known each other for years, with Elton even giving the One Direction alum a shout-out during his iTunes Festival show in London in 2013. Harry posted a photo with Elton at the show, calling him a "living legend."
Beyoncé as Toni Braxton
Not even the R&B legend herself could believe just how perfectly Queen Bey pulled the costume off in 2018. "Phoni Braxton!? NEVER!!! How do you look better than me on MY album cover?" she tweeted. "I LOVE IT, Such a superstar! Thanks for the love sis!"
Rita Ora as Post Malone
The British pop star pretty much won Halloween 2018 with her spot-on recreation of the "Better Now" rapper during a performance in the U.K.
Chrissy Teigen & John Legend as Queen Elizabeth II & Prince Philip
The duo decided to dress up as another iconic couple in 2018: Queen Elizabeth II and the Prince Philip. They shared photos and videos with their followers, with the musician joking, "We worked all day. We just did it for the 'gram."
Gabrielle Union as Gwen Stefani
Dwyane Wade threw his wife an epic birthday-Halloween bash in 2018, where attendees dressed up in their favorite '90s ensembles. No doubt she looked B-A-N-A-N-A-S.
Gus Kenworthy as Adam Rippon
The Olympic skier dressed as "Adam Ripoff" for a Halloween party, wearing an outfit similar to the Olympic figure skater's 2018 Oscars ensemble, complete with a harness.
"We finally did each other," Adam replied to Gus' costume on Twitter. He also asked his social media followers, "Where were you when @guskenworthy won Halloween?"
Nicky Hilton as Paris Hilton
Nicky dressed up as her sister Paris for the Casamigos bash in 2018, donning a replica of her sister's iconic 21st birthday dress and choker.
"I searched and searched for a costume and I couldn't find anything," Nicky told E! News exclusively at a fundraiser for Race to Erase MS later that weekend. "I didn't want to buy something from one of those plastic bags so I called up Paris and said, 'By any chance, do you still have that dress?' And she did."
As for what Paris thought of her costume, Nicky said, "She loved it."
Erin Foster as Hailey Baldwin
Erin and now-husband Simon Tikhman dressed up as Hailey Baldwin and Justin Bieber for Kate Hudson's Halloween bash in 2018. Erin is connected to Hailey through the model's close pal Gigi Hadid, whose mom Yolanda Hadid used to be married to Erin's dad, David Foster.
"Is it too late now to say sorry?" Erin captioned an Instagram post with her "Justin."