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At his "Harryween" concert in Madison Square Garden, Harry Styles' wore a micro gingham frock, red slippers and a bow as Dorothy from "The Wizard of Oz."
DIGGZY/Shutterstock
Lizzo painted herself green, pulled on a pair of Uggs and wore a tan cloak as Baby Yoda from "The Mandalorian."
Amy Sussman/Getty Images
Jamie Lee Curtis paid tribute to her mother Janet Leigh, wearing an outfit inspired by Leigh's costume in "Psycho" -- complete with a bloodied shower curtain.
From @sophiet/Instagram
Joe Jonas gave his past Disney days a nod and celebrated Halloween dressed as Paolo from "The Lizzie McGuire Movie," alongside Sophie Turner and Olivia De Jonge as Lizzie McGuire and her doppelganger Isabella.
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Michael Jackson's daughter, Paris, took inspiration from art history with a Van Gogh-inspired look.
From @katyperry/Instagram
Katy Perry dressed as a syringe, while Orlando Bloom sported PPE as a doctor.
Amy Sussman/Getty Images
Actor Judy Greer attended a "Halloween Kills" premiere as the Diane Keaton character, Annie Hall.
Denise Truscello/WireImage/Getty Images
Rapper Cardi B dressed as a nun as she performed at a nightclub opening.
From @johnlegend/Instagram
John Legend and Chrissy Teigen came dressed as members of the Addams Family, with their daughter Luna dressed as Wednesday.
Robin L Marshall/Getty Images
Rapper Doja Cat attended a Halloween party dressed as Miss Bellum from the "Powerpuff Girls," along with a Mr. Mayor stuffed toy pinned to her lapel.
Mike Marsland/WireImage/Getty Images
Little Mix singer Jade Thirlwall attended a Halloween party dressed as Marge Simpson, accessorized with the remains of Homer Simpson.
From @lalalalisa_m/Instagram
Blackpink member Lisa channeled this year's biggest Netflix hit, "Squid Game," by wearing the costume from the gory Red Light, Green Light game.
From @shawnmendes/Instagram
Shawn Mendes and Camilla Cabello celebrated Dia de los Muertos early in makeup and florals.
CNN  — 

Childhood movie throwbacks, “Squid Game” characters and some impressive prosthetics featured among 2021’s best celebrity Halloween costumes, with stars including Katy Perry, Doja Cat and John Legend getting into the holiday spirit.

Though several major Halloween parties, like Heidi Klum’s annual bash, were put on hold this year, fellow model Alessandra Ambrosio hosted a star-studded bash and Harry Styles invited fans to dress up in costume for his “Harryween” concert at Madison Square Garden. (Styles, of course, came dressed as Dorothy from “The Wizard of Oz,” complete with a gingham micro dress and ruby red slippers.)

Pop culture references were out in force, with Lizzo dressing up as Baby Yoda, Blackpink’s Lisa channeling the eerie Red Light, Green Light girl from “Squid Game” and former figure skater Adam Rippon dressing up as Nicki Minaj’s Twitter-infamous cousin. Megan Thee Stallion, who has sported a variety of different Halloween outfits in recent days, gave Emma Stone a run for her money as Cruella de Vil.

Others went all out with elaborate special effects: Ariana Grande transformed herself into a mossy swamp monster and Lil Nas X appeared as Voldemort on Instagram. Janelle Monae started Christmas early with a scarily accurate “The Grinch” costume, while Kendall Jenner and Reese Witherspoon dove into the Hollywood archives appearing as the Martian Girl from the 1996 cult film “Mars Attacks!” and Melanie from the Hitchcock classic “The Birds,” respectively.

Scroll through the gallery above for some of the year’s best Halloween costumes.