Wonderwall.com is taking a look back at the year's biggest celeb hair transformations, starting with this major switch-up… After previously sporting bleached-blonde hair with dark roots, Kristen Stewart debuted a new all-over strawberry blonde look at September's 78th Venice International Film Festival in Italy, where she promoted her November 2021 film "Spencer," in which she plays Princess Diana.
Keep reading to see more of the year's biggest celebrity hair transformations…
RELATED: Celeb weight loss transformations
Seth Rogen has long sported short but kind of poofy hair and a beard or scruff, like he did at this event in July. But in September, he got a major cut and shaved, revealing a shockingly different appearance. "New hair, same smoldering look," Seth captioned this selfie revealing his fresh new close-cropped haircut and trimmed facial scruff on Sept. 1.
Magnolia Network founder and "Fixer Upper" star Chip Gaines let his hair grow and grow during the COVID-19 pandemic. Then he cut it all off on Aug. 27 — and documented the process on Instagram to raise money for St. Jude Children's Research Hospital. Keep reading to see Chip without any hair, and to find out how much money he helped raise…
Chip Gaines shaved his head on Aug. 27 to raise money for St. Jude Children's Research Hospital and showed off his before-and-after photos on Instagram. (The Magnolia Network founder got his major haircut alongside Bailey, a 16-year-old St. Jude patient who's now cancer-free — and also free of his own long hair after getting the chop alongside the "Fixer Upper" star.) "WOW.. over $425k raised for @stjude!! We are completely blown away by how y'all came together to chip in for this amazing organization. [My wife] Jo and I are rounding that number up to an even $500k & we're also sending $50k to the folks over at @cwhl_org [Children With Hair Loss] to support the work they're doing," Chip wrote on Instagram. "Thank you all for being a part of this with us—what a powerful week that will no doubt have a lasting impact on countless lives. #ChipInForStJude."
On Aug. 27, Audrina Patridge revealed that her stylist, Wella Professionals North America Ambassador Briana Cisneros, used Wella Professionals' Koleston Perfect to dye her hair a pretty pink shade. "After going 'sandy blonde,' I wanted to turn it up a notch — and it's true, you can really have fun without compromising hair health. I am so grateful to have my stylist along with me on this ride and excited to be heading into fall with a positive outlook and these pinky tones," said the longtime star of "The Hills."
Actor Dylan O'Brien went from brunette to blonde as he prepared to film the satire "Not Okay," as seen in a TikTok video re-posted to the movie's official social media accounts on Aug. 17.
On Aug. 20, Chrissy Teigen took to Instagram to show off her fresh bob haircut, which was apparently inspired by Kourtney Kardashian! "Cause @kourtneykardash looked so keeeeyute!" the model-entrepreneur — who had slightly longer shoulder-length hair before her latest trim — captioned a short video.
Keep reading to see the cut that inspired Chrissy's look…
Upon returning home to Texas from Tokyo after winning two medals in the Summer Olympics, gymnast Simone Biles revealed a new post-Games look: She traded the shorter, straight hair she'd worn in an updo during competition for a fresh long braided and curled hairstyle, seen here in an image she shared on her Instagram Story on Aug. 8.
"So, I did a thing 🤗 The movies always show women cutting their hair when all is lost but I wanted to know the feeling of making a change when things are gravy. It hits different and its foreign to me but I ❤❤❤ this new new. #SummerChop #FlawlessChop #FlawlessCut," Gabrielle Union captioned this selfie revealing her new short hair on Instagram on July 23.
Model-actress Iris Law shaved her head to play Soo Catwoman on the upcoming FX series "Pistol," which chronicles the rise of the British punk scene. On July 1 in a piece for British Vogue, the beauty revealed she'd buzzed off her long brown locks instead of wearing a wig. "I wanted to do something that felt liberating. The day I shaved my head, I changed my life. I've never done anything like that before," Iris, the daughter of actor Jude Law and former model-designer Sadie Frost, told the magazine. She later posted more photos of her new short platinum look — her eyebrows were bleached too — on Instagram including this July 2 snapshot.
Courtney Stodden ditched their trademark long platinum blonde hair and debuted a new lob haircut in a flattering dirty blonde shade for the summer. "New hair who dis? #bobhaircut #naturalhair #nomakeup *ignore the busted manicure 💅 🤣," Courtney captioned this selfie on June 27.
"Game of Thrones" alum Sophie Turner debuted some new fringe on May 28. "Ya gal's BANG'd up," the actress captioned this selfie revealing her new bangs on her Instagram Story.
"The Crown" star Emma Corrin debuted a new super-blonde shorter hairstyle on Instagram on May 20. The star's new '90s-inspired cut with curtain bangs came courtesy of celeb hairstylist Daniel Martin, whom she tagged in the caption.
On May 19, Mandy Moore revealed she'd lightened her dark brown hair at home using a box dye kit — Garnier Nutrisse in shade Dark Blonde 70 Almond Crème. "It's so much fun to be blonde again, and I'm completely in love with my new hair already," the natural blonde captioned a transformation video on Instagram. A few days later on May 25, she showed off her new hue in person at 20th Television & NBC's "This Is Us" FYC drive-in screening and panel in Pasadena, California.
After weeks of sporting a head full of short dreadlocks, sparking cultural appropriation criticism from some fans, pop star Justin Bieber revealed he shaved his head over the weekend of May 22. "Happy Sunday," he captained this selfie he snapped while out to eat with wife Hailey Bieber on May 23.
After years of long locks, Rihanna revealed a fresh new short pixie-cut hairstyle as she arrived for dinner at Giorgio Baldi in Santa Monica on May 5.
Paris Hilton cut her long blonde locks into a shoulder-length bob in early 2021. She showed off her new look during a night out in Los Angeles on April 21. The following day, she said on the April 22 episode of her "This Is Paris" podcast that her fresh cut is inspired by journalist Katie Couric's signature 'do. "I love it — I think it looks so chic. It's beautiful, and I told her I was going to copy her hairdo," she revealed.
Halle Berry debuted a new look — a blunt bob and bangs — at the 2021 Oscars on April 25. She took to her Instagram Story to share a snap of hair clippings, indicating her fresh cut was the real deal and not a wig — as many fans speculated (and hoped). On April 30, she revealed her divisive new 'do was, in fact, a wig: "Oscar bob…just kidding," she captioned a photo of herself with shoulder-length locks.
Natural brunette Selena Gomez debuted a fresh blonde 'do on April 23. "New look. Need to pick new Rare Beauty lip and blush shades now 💓," the singer-actress, who launched her Rare Beauty makeup brand in 2020, captioned this selfie she posted on her own Instagram Stories as well as her Rare Beauty Instagram account.
On April 8, Hilary Duff revealed on Instagram that she went back to blonde (and got major extensions!) after dying her hair a bold blue shade in February. "Have you noticed that I'm blonde…. and Rapunzeled???" she captioned this selfie. She then profusely thanked her hairstylist, writing, "@nikkilee901 you are hair fairy goddess and I thank you for going down all my hair-ventures with me. Especially for all the tender loving care you treat my hair with when you have to undo what I make you do. She loves me…. she really really loves me. Thanks for making this lady feel half summer ready…. Now what can you do for a post baby bod???" (Hilary just welcomed her third child in late March.)
On April 12, Lucy Hale took to Instagram to reveal she shortened her shoulder-length locks and then dyed her tresses platinum blonde after rocking a golden shade earlier this year. She captioned this selfie with lemon, honey and scissor emojis and tagged her colorist and stylist.
On April 6 — after teasing fans with pink Instagram filters and wigs for months — model and cookbook author Chrissy Teigen took to her Instagram Story to reveal she'd had her hair bleached and dyed for real as she debuted pretty new pale pink locks.
Actress Zooey Deschanel showed her followers what she looks like without the trademark bangs she's sported for years, captioning this March 26 Instagram selfie, "For all the doubters…" and adding the message, "Proof I have a forehead." Ha!
On March 22, "The Real Housewives of New York City" star Leah McSweeney — who's usually blonde — posted this selfie on her Instagram Story revealing her new red hair color. The Married to the Mob designer also asked followers what she should call the shade. "Pandemic red?" she mused, adding, "Possibly not appropriate."
In late March, "Agents of S.H.I.E.L.D." star Chloe Bennet dyed her hair auburn for her role as Blossom in the upcoming live-action reboot of the iconic cartoon "The Powerpuff Girls." She took to Instagram on March 23 to show off the results, captioning a video of herself, "A female, asian, red headed, superhero (again). … Go ahead and normalize being anything you want hunnyyy."
On March 17, Billie Eilish debuted her new platinum blonde locks on Instagram. "Pinch me," she captioned this shot of herself, referencing the fact that she'd shed her iconic black-and-green look just in time for Saint Patrick's Day when people typically wear green. Her hairstylist later revealed that it took six weeks for them to achieve the chart-topper's new look, and Billie admitted she'd been secretly wearing a wig for "like 2 months."
Machine Gun Kelly started 2021 with bleached blonde locks, but he dyed his hair a turquoise shade sometime in mid-March. He debuted his new look during a dinner date with Megan Fox in Los Angeles on March 18.
On March 17, model Barbara Palvin took to Instagram to share this selfie with boyfriend Dylan Sprouse. In the process, she revealed that the former child star had bleached his hair.
Grace VanderWaal made waves in late 2020 when she suddenly shaved her head. In early 2021, after her hair grew out a bit, she dyed it blue. "Hey," the "America's Got Talent" alum captioned a slideshow of mirror selfies debuting her new look on March 15.
On March 13, Addison Rae rocked her natural brunette locks in a topknot on the orange carpet at the 2021 Nickelodeon Kids' Choice Awards. (Take a look here.) Four days later, she took to Instagram to share a selfie showing off her newly blonde mane.
Gigi Hadid, who typically rocks blonde locks, dyed her hair auburn in early 2021. Her hairstylist, Panos Papandrianos, showed off his creation on Instagram on March 5. "Ginger for Gigi," he captioned a slideshow of photos and videos debuting the model's new look, adding in a hashtag that they were "playing with colors."
Carrie Ann Inaba took to Instagram on March 6 to show off the new blonde highlights in her naturally brunette locks. "I like highlights. What can I say," she captioned this selfie.
Olivia Rodrigo got bangs! The "Drivers License" chart-topper took to Instagram on March 3 to show off her new 'do. "Not the bayang," she captioned this mirror selfie.
On Feb. 19, Hilary Duff revealed on Instagram that she dyed her hair blue after wrapping the seventh and final season of "Younger," which films in New York City. "The minute I got home from New York, I needed a change," she captioned a slideshow of photos of her "crazy change," including this selfie. The pregnant actress went on to say that the dye job wasn't meant to serve as an indication she's expecting a son: "I swear this doesn't mean I'm having a boy… my mom thought I was trying to tell everyone something! We still don't know who's occupying my apartment – but it's getting the eviction notice soon-ish," she joked.
Scott Disick spent the first few months of 2021 trying out different hair colors. First, in mid-February, he bleached his hair. (See that look here.) A few days later, he dyed his hair pink. He showed off his latest look in this shot of himself on a private jet, which he posted on Instagram on March 1.
Rep. Alexandria Ocasio-Cortez, who represents New York's 14th congressional district, debuted her new lob in an hourlong March 11 Instagram video breaking down the United States' new COVID relief bill. After fans started calling out her fresh cut, AOC — who started the year with significantly longer locks — reportedly joked, "Oh, you guys like my haircut — you guys are talking about it. Let's not start a national crisis about it!"
In February, Sarah Hyland dyed her naturally brunette locks a pretty auburn shade. "Getting back to my Scottish/Irish roots. Also, I'm bored and watched all of 'Outlander' for a second time," the "Modern Family" alum captioned this selfie debuting her new look on Instagram on Feb. 24.
Lily Allen has sported bangs for a while now, but she debuted super-short blunt fringe in February. She took to Instagram to share this mirror selfie showing off her new look on Feb. 26.
Shawn Mendes's hair was so long in January, he was able to pull it back into a small ponytail! (See it here.) Not long after that, he got a fresh cut, which he showed off on his Instagram Story on Feb. 18. "Goodbye long hair!!" he captioned a selfie video.
Hairstylist Chris McMillan lightened Jennifer Aniston's locks when it was time for her to start shooting the second season of "The Morning Show." The Emmy-winning actress took to Instagram on Jan. 26 to show off his work, captioning a slideshow of selfies, "Aaand, we're back…"
Taraji P. Henson kicked off 2021 by dying her hair purple. "New Year New Color #2021 the year of royalty," the Oscar-nominated actress captioned this selfie showing off her new hue on Instagram on Jan. 2.
Taraji P. Henson didn't stick to purple for long. On Jan. 11, she took to Instagram to share a slideshow of photos showing off her new deep-pink shade, which she captioned with a hashtag for "hair chameleon."
Tiffany Haddish debuted a new look — bleached blonde hair! — on the red carpet at the 2021 Golden Globe Awards on Feb. 28.
Before she bleached her hair, Tiffany Haddish got a buzzcut with her catchphrase — "She Ready" — shaved into the back. "Results of the She Ready hair cut by @lamarr_randle. I Love this haircut!!!!" the comedian captioned a video on Instagram on Jan. 18.
Early in 2021, former "The Bachelorette" star Clare Crawley used hair-coloring shampoo and conditioner to briefly dye her tresses pink. "I've been wanting to have some fun and (temporarily) change up my hair for some time now with a fun color, so I did it!!" she captioned a photo of herself on Instagram on Feb. 6. She also took to her Instagram Story to share this selfie.
When Lady Gaga performed at President Joe Biden's inauguration on Jan. 20, she wore her platinum blonde locks in crown braids. (Take a look back here.) A month later, on Feb. 24, she debuted a new style during an outing in Rome: She dyed her hair chocolate brown for her role as Patrizia Reggiani in the upcoming biopic "House of Gucci."
Ricky Martin started the year with totally average facial hair. But things soon took a dramatic turn. He debuted his new look — a bleached beard — on Instagram on Jan. 21. "When bored, bleach," he captioned this selfie. (As of mid-March, he was still rocking the unique facial hair.)
In January, Ana de Armas cut her long brunette mane into a choppy bob with bangs. She took to Instagram on Jan. 30 to show off her new look in this selfie.