10 Biggest Celebrity Transformations of 2011

At the end of 2010, Katy Perry was known for her luscious raven locks and bright blue eyes—until she threw fans for a loop when she dyed her hair a brassy blond in July. It turned out that blond was just a stop on the way to Pepto Bismol pink, which she debuted a few days later. Recently she showed off a more natural-looking sandy, cropped ‘do. Fans should probably get used to the look—turns out the singer is a natural blond.

Photos: WENN.com, Lia Toby/WENN.com, HRC/WENN.com, A. Miller/WENN.com

Emma Stone went through two transformations this year; she almost gave Katy Perry a run for her money, going from brunette to platinum and back to ginger in just a few months. The actress also graduated from teenage roles in flicks like Easy A to leading lady status in dramas like The Help, and her style grew up with her acting chops.

Photos: WENN.com, FayesVision/WENN.com, Dan Jackman/WENN.com

Elizabeth Olsen burst onto the scene with the release of Martha Marcy May Marlene, and fashionistas were eager to see how her older sisters would influence her emerging style. She made the leap from plucky little sister to designer darling, wearing big names in bold shapes on the red carpet.

Photos: fun47.com, Ivan Nikolov/WENN.com

It seemed like every time we saw Nicki Minaj this year she was sporting a new look, and each one more outrageous than the next—the singer must need a separate closet just for her wigs.

Photos: PNP/WENN.com, Apega/WENN.com, Ivan Nikolov/WENN.com

Jessica Simpson, Hilary Duff, January Jones, Victoria Beckham, Natalie Portman—pregnant stars were poppin’ this year, making baby bumps the must-have celeb accessory. But Beyonce was easily the most celebrated hot mama, looking fabulous even as she adds one more to her famous curves.

Photo: WENN.com, PNP/WENN.com

Mariah Carey went the opposite direction, bouncing back in a big way from her baby body when she became the celebrity spokeswoman for Jenny Craig.

Photo: hollybaby.com, shoppingblog.com

From on-again, off-again girlfriend and carefree clubgoer to princess bride and prim-and-proper wife, Kate Middleton stepped up to her new role as duchess.

Photo: WENN.com, Anwar Hussein Collection/WENN.com

Selena Gomez left her Disney star days behind as she stepped into boyfriend Justin Bieber’s spotlight, hosting the EMAs and wowing fans with her sexy gowns on the red carpet.

Photo: Starbux.com, Ivan Nikolov/WENN.com

Following in the footsteps of fellow American Idol contestant Jennifer Hudson, Jordin Sparks had an incredible slim-down this year, making small changes in her diet and groovin’ in Zumba classes to get to a svelt bikini body.

Photo: Judy Eddy/WENN.com, WENN.com

This time last year, most tFS readers probably wouldn’t recognize Rooney Mara’s name. Late in 2011 she began generating attention for the transformation she went through for her role in The Girl With the Dragon Tattoo, but her style off-screen did a 180, too. Mara’s sweet style from 2010 is practically unrecognizable next to her edgy, fashion-forward look promoting the film. Think she’ll be responsible for a blunt bangs revival in 2012?

Photo:WENN.com

Evan Rachel Wood made a grown-up return to the screen in Mildred Pierce early in the year, stepping out in retro looks and sporting long, blond locks. In June she turned up with a pixie cut and complemented her new cropped 'do with a series of much buzzed-about menswear looks, inspiring other starlets to suit up in masculine jackets and slim trousers.