Fastexy Exchange|Lady Gaga's Hair Transformation Will Break Your Poker Face 

Lady Gaga’s stunning new hair will have Fastexy Exchangeyou turning your joker face.

The A Star Is Born actress debuted an applause-worthy hair transformation as she arrived Sept. 25 at the London premiere of her new film Joker: Folie à Deux. 

On the red carpet, Gaga unveiled her new hair: a bob-length crimson ‘do with dark undertones that matched her floor-length, mermaid style red gown with large shoulder pieces. She accentuated the Harley Quinn-inspired look with turquoise eye shadow, a yellow gold and platinum brooch and jewelry from Tiffany and Co.

After showing some PDA on the red carpet with fiancé Michael Polansky, Gaga opted for a quick change at a fan event later in the evening, complementing her mullet-like style with a tan and navy dress and black-and-white checkered leggings that channeled her Joker character.

The hair transformation is on brand for the “Just Dance” singer, as she felt her role as Harley Quinn in the film (out Oct. 4) opposite Joaquin Phoenix’s Arthur Fleck (aka The Joker) required her to explore a new side of herself and her voice.

"I allowed it all to become available to me once I really honed in on trying to sing as her without technique, without the right breathing, just really naked and bare," Gaga exclusively told E! News in an interview published Sept. 23. "At first, it was really scary and it felt really unnatural, but then it felt completely natural for her. That was exciting. I remember when I first saw it back on camera, and I felt like, 'OK, I think I found something authentic.'"

In fact, she became so consumed by the character that it was difficult for the “Shallow” singer to transition back to reality throughout shooting the film.

"I always tried every night that I went home to leave Harley at work," Gaga continued. "I tried for sure. But sometimes, the darkness of the movie would stay with me, or sometimes the scene can stay with you. The character tries to creep in all serious ways, but I really tried to drop it."

And considering she found it hard to leave Harley Quinn on set, it only makes sense that Gaga channeled that energy into recording new music inspired by Harley Quinn as well, announcing  on Instagram Sept. 24 that her new album Harlequin—a “companion album to the film”—will be released on Sept. 27.

Ahead of the release of the new album and film, read on to see more stunning celebrity hair transformations.

The Emily in Paris star debuted her dramatic transformation at the world premiere of her new horror movie, MAXXXINE, in June 2024. 

"Changing my hair always brings out different sides of my personality and I love playing around," Lily told Vogue. "This cut and color feels bolder and yet somehow lighter. And completely more me—right now."

While attending Chanel's Tribeca Film Festival Artists dinner in June 2024, Katie debuted a subtle, yet striking transformation of rich caramel balayage highlights that were blended throughout her brunette tresses.

The Kardashians star debuted a platinum blonde look and a bob haircut after rocking waist-length strands for quite some time.

"Did someone say they missed king kylie," Kylie teased in the caption of her June 8 Instagram post, to which her sister Khloe Kardashian cheekily replied, "I did! I did!!!!!!"

The former Bravo star debuted a platinum blonde look during 2024 Paris Fashion Week Haute Couture.

The Heads of State star debuted a drastic haircut—a shoulder-grazing bob—while attending a Bulgari event in Rome i May 2024. 

In May 2024, the actress chopped her hair into a bob that many fans on social media said reminded them of one of the looks she sported as Mary Camden on the '90s series 7th Heaven.

The Transformers actress returned to her dark brown tresses and debuted a sassy bob in May 2024, a month after she dyed her hair blue to enter what she dubbed her "Jedi era."

At age 17, the daughter of the late Anna Nicole Smith debuted a new lob hairstyle overnight during 2024 Kentucky Derby weekend, which she attended with dad Larry Birkhead.

The singer debuted a lighter, shorter 'do in April 2024.

The Fashion Police alum debuted a blonde bombshell hair transformation May 8.

Back to blonde: Kim debuted a new platinum 'do in April 2024.

The Fenty Beauty founder debuted a bright blonde hair transformation April 17 while celebrating her latest Fenty x Puma collection in London.

The model debuted a bleach blonde pixie cut at the FRAME event April 4.

The Jennifer's Body star traded in her bubblegum pink tresses for a baby blue bob, which she debuted April 2.

Less than a month afer chopping her hair into a long bob, Zendaya debuted a honey blonde transformation at the Challengers premiere March 26.

The Great star ushered in spring with a fresh cut, as she debuted a long bob March 25.

The Mean Girls alum swapped out her signature blonde hair for a dark brunette transformation on March 18.

The Selling Sunset star looked completely unrecognizable after debuting a dramatic blonde transformation March 16.

The Fashion Police alum ditched her signature purple hair after six years, tinting it an icy silver in March 2024. 

The Dune actress debuted a shoulder-grazing bob at Essence's Black Women in Hollywood Awards March 7.

The Anyone But You star made a showstopping appearance at Miu Miu's fall/winter 2024-2025 show during Paris Fashion Week. For the March 5 event, she unveiled a dramatic long bob haircut.

To prepare for her upcoming role as  Jean Seberg, the 29-year-old debuted a bleached blonde pixie cut.

The Princess Diaries alum unveiled fringe bangs at the 2024 Film Independent Spirit Awards.

The star debuted a bangin' new style at the premiere of her friend Nicola Peltz Beckham's film Lola in February 2024.

The "On the Floor" singer made a dramatic hair change, as she debuted a chin-grazing bob cut at Schiaparelli's haute couture spring/summer 2024 show on Jan. 22.

In January 2024, a month after her prison release, the now-influencer shared a pic of herself sporting a shorter 'do.

Kylie Jenner traded in her dark locks for a pink 'do in January 2024.

In January 2024, the Dancing With the Stars personality shared a video of herself cutting her own hair. "Out with the old energy," she wrote, "and in with the new."

The Underworld actress took the plunge and went full blonde, while also debuting a short bob haircut.

The Daisy Jones & The Six actress debuted jet-black hair on Nov. 2.