Upton attended a casting call in Miami for Elite Model Management in 2008 and was signed by them the same day, and she eventually moved to New York City, where she then signed with IMG Models.
Upton first modeled clothing for Garage and Dooney & Bourke.She was the 2010–11 face of Guess. In 2011, Upton appeared in the Sports Illustrated Swimsuit Issue.]She was featured in the body paint section and named Rookie of the Year for that issue. She has since modeled for Beach Bunny Swimwear, and has appeared in Complex andEsquire as “The Woman of the Summer”. Upton wore one of the Beach Bunny suits in the 2014 Sports Illustrated Swimsuit Issue.
In April 2011, an Internet video of her doing the dougie hip-hop dance at a Los Angeles Clippers game went viral and served to increase her popularity Guy Trebay of The New York Times observed that this served to illustrate the power of social media to bestow stardom upon a model, which had previously been the domain of top designer runway shows. In April 2012, Upton appeared in a video of herself performing the Cat Daddy dance to the song of the same name by The Rej3ctz, which also went viral.
Upton made an appearance in a June 2011 episode of Tosh.0and participated in the 2011 Taco Bell All-Star Legends & Celebrity Softball Game at Chase Field in Phoenix, Arizona, in July 2011.
Upton’s acting debut was in the film, Tower Heist, as Mr. Hightower’s Mistress. It was released in November 2011. She also appeared in The Three Stooges as Sister Bernice.
Upton appeared on the cover of the 2012 Sports Illustrated Swimsuit Issue, released in February 2012.As of that month, her Twitter account had a following of 170,000 people. Upton has also recounted the negative aftereffects of the 2012 Sports Illustrated cover, saying, “I felt terrible about myself for a solid month. Every single guy I met was either married or about to be married, and I felt like I was their bachelor present or something.”
Upton has appeared on the covers of Vogue Italia, British Vogue, CR Fashion Book, Cosmopolitan, French ELLE, GQ, Italian GQ, German GQ, Jalouse, Sunday Times Style, Esquire, The Daily, and Muse Magazine.
In 2012, she was ranked the fifth sexiest model by MODELS’s.She ranked #3 on the American publication of AskMen’s Top 99 Women for 2013.In 2012, she was listed on Maxim‘s HOT 100 list, citing her photo shoots with Sports Illustrated.
Upton was the cover model for the 2013 Sports Illustrated Swimsuit Issue for the second consecutive year. Parts of her 2013 Sports Illustrated pictorial were filmed in Antarctica and Upton suffered from failing hearing and eyesight due to the extreme cold.
After getting the November 2012 Vogue Italia cover photographed by Steven Meisel and the January 2013 Vogue UK cover, Upton landed the June 2013 Vogue cover by Mario Testino. She was then photographed byAnnie Leibovitz for the October 2013 100th anniversary cover of Vanity Fair.
In September 2013, Upton was named Model of the Year at the 10th annual Style Awards at the Mercedes-Benz Fashion Week in New York.
Upton appeared on the flip-side cover of the 2014 50th anniversary Sports Illustrated Swimsuit Issue, the first time that type of cover was used by that magazine.Part of her shoot took place at Cape Canaveral, capturing her inzero gravity