Renee Zellweger, who is known for her trademark cheeks, surprised many onlookers on the red carpet of ELLE's 21st annual Women In Hollywood Awards in Los Angeles on Monday with a very different look.

The 45-year-old actress, who is known for her angelic look, shocked many on the red carpet at the Four Seasons Hotel, California, as she was almost unrecognizable, making many believe that she might have undergone plastic surgery.

The Oscar-winning actress has not admitted to going under the knife but she raised many eyebrows by appearing on Monday with altered brows, line-free forehead, and her face looks so different.

Experts think that the actress might have gone for plastic surgery.

"The extra hooded skin on her eyes isn't there anymore," Dr. Robert Guida, a plastic surgeon on Park Ave., told Daily News, adding that she might have "got Botox and fillers in her face." 

"There is no question she has had her upper eyelids done," Dr. Thomas Sterry, a Manhattan plastic surgeon told the website. "She always had that cherub-y face, and suddenly ... her eyes (are) much wider."

Dr. Victoria Karlinsky, a cosmetic surgeon on the Upper West Side, also said that the actress seemed to have got a nose job, as "The bridge of her nose has become more narrow."

"When people got up close to her, they were taken back by what she had done to her face," a source told the website. "Everyone was whispering about how different she looked."

Dr Alex Karidis of London's Karaidis Clinic, also told MailOnline that the actress might have done an upper eye lift, as "the distance between the brow and her eye is much smaller than before" but might not have gone for a brow lift. 

"Her forehead is smooth - you would expect more expressive wrinkles when she smiles which indicates a possible small dose of Botox between the eyelid and eye," he added.

Renee Zellweger might have gone under the knife or might not have but her new look will surely draw different opinions from the public.

Fahra Simon, a 28-year-old health specialist, slammed the actress' new look, and told Daily News that "She's probably having a mid-career crisis!" adding, "A lot of celebrities are trying to keep up with the younger generation, the Kim K's."

On the other hand, Jane Reid, a 58-year-old legal assistant from Staten Island, told the website that "She got work done, but she looks better now." Karlinsky also said that the actress might be simply ageing gracefully and that "She's still a beautiful woman."

Renee Zellweger
Actress Renee Zellweger poses at the 21st annual ELLE Women in Hollywood Awards in Los Angeles, California October 20, 2014.Reuters
Renee Zellweger
Actress Renee Zellweger poses at the 21st annual ELLE Women in Hollywood Awards in Los Angeles, California October 20, 2014.Reuters
Renee Zellweger
Actress Renee Zellweger poses at the 21st annual ELLE Women in Hollywood Awards in Los Angeles, California October 20, 2014.Reuters
Renee Zellweger
Actress Renee Zellweger arrives at the Metropolitan Museum of Art Costume Institute Benefit celebrating the opening of "PUNK: Chaos to Couture" in New York, May 6, 2013.Reuters
Renee Zellweger
Actress Renee Zellweger arrives at the Metropolitan Museum of Art Costume Institute Benefit celebrating the opening of the "Schiaparelli and Prada: Impossible Conversations" exhibition in New York May 7, 2012.Reuters
Renee Zellweger
U.S. actress Renee Zellweger arrives on the red carpet for the 46th 'Goldene Kamera' (Golden Camera) awards ceremony at the Ullstein Auditorium in Berlin, February 5, 2011.Reuters
Renee Zellweger
Actress Renee Zellweger attends "CNN Heroes: An All-Star Tribute" in Los Angeles November 20, 2010.Reuters