Gisele Caroline Bündchen (Brazilian Portuguese: [ʒiˈzɛli ˈbĩtʃẽ], German: [ˈbʏntçn̩]; born 20 July 1980) is a Brazilian supermodel and activist. Since 2001, she has been one of the highest-paid models in the world. In 2007, Bündchen was the 16th-richest woman in the entertainment industry and earned the top spot on Forbes highest-paid models list from 2005 to 2016. In 2014, she was listed as the 89th most powerful woman in Media and Entertainment by Forbes.

Vogue credited Bündchen with ending the heroin chic era of modeling in 1999. She was a Victoria's Secret Angel from 1999 until 2006. Bündchen is credited with pioneering and popularizing the horse walk, a stomping movement where a model lifts her knees high and kicks her feet to step. In 2007, Basia Kolen called Bündchen the only remaining supermodel. She has appeared on more than 1,200 magazine covers.

Bündchen was nominated for Choice Movie Female Breakout Star and for Choice Movie Villain at the 2005 Teen Choice Awards for her supporting role in Taxi (2004). She had a supporting role in The Devil Wears Prada (2006) and was the executive producer of an educational environmental cartoon, Gisele & the Green Team, in 2010 to 2011. In 2016, Bündchen appeared in the Emmy Award–winning documentary series Years of Living Dangerously, in the episode "Fueling the Fire". Her charitable endeavors include Save the Children, the Red Cross, and Doctors Without Borders. Bündchen has been a Goodwill Ambassador for the United Nations Environment Program since 2009.

Gisele Caroline Bündchen, a sixth-generation German Brazilian, was born on 20 July 1980 in Horizontina, Rio Grande do Sul, to Valdir Bündchen, a university professor, and Vânia Nonnenmacher (1948–2024), a banker. Her grandfather, Walter Bündchen, once served as mayor of Horizontina. Bündchen grew up with five sisters including a fraternal twin. The family is Catholic. Although her parents speak German and Bündchen studied German in school, she never truly learned the language. Besides her native Portuguese, Bündchen speaks English fluently, some broken Spanish which native speakers have dubbed "portunol" and which she punctuates with English words, as well as a few very basic sentences of rudimentary French, which she has expressed a desire to eventually learn.

Bündchen aspired to be a volleyball player, but in 1993, her mother enrolled her and her sisters, Patrícia and Gabriela, in a modeling course to teach them confidence and better posture. After the course ended, the girls were rewarded by a trip to Curitiba, São Paulo and Rio de Janeiro, where Bündchen was discovered by Elite Model Management at a shopping center. She was placed second in a national contest, Elite Model Look, that was then known as Look of the Year. In 1995, Bündchen moved to São Paulo to launch her modeling career. The following year, Bündchen debuted at New York Fashion Week.

Bündchen began her modelling career in 1996. The following year, she was rejected 42 times in London before being cast in an Alexander McQueen runway show in 1998. In 1998, Bündchen posed for Missoni, Chloé, Dolce & Gabbana, Valentino, Gianfranco Ferré, Ralph Lauren, and Versace campaigns. She appeared on the cover of Vogue Paris, her first cover of British Vogue, and i-D, which featured her on its cover, profiling "A Girl Called Gisele". Dissatisfied with Elite Model Management's work environment, Bündchen signed with IMG Models in 1999.

Bündchen's first U.S Vogue cover, where Vogue announced Bündchen was "the return of the sexy model", was the first of three Vogue covers for her in 1999. In November, she appeared in a group Vogue cover with Kate Moss, Amber Valletta, Christy Turlington, Iman, Lauren Hutton, Naomi Campbell, Stephanie Seymour, Claudia Schiffer, Lisa Taylor, Paulina Porizkova, Carolyn Murphy, and Patti Hansen, and appeared in a solo U.S. Vogue cover in December. Bündchen won the VH1/Vogue Model of the Year in 1999. After appearing in five major campaigns at age 18, New York magazine editor Sally Singer deemed Bündchen an "über" model.

Bündchen became the fourth model to appear on the cover of Rolling Stone magazine when she was named "The Most Beautiful Girl in the World" in 2000. In 2000, Vogue's online encyclopedia of models described Bündchen the world's hottest model and referred to her as "the Brazilian bombshell". That same year, Bündchen fronted the advertising campaign for Dior's newly launched Dior Saddle bag, photographed by Nick Knight. The campaign, which also featured model Rhea Durham, was part of John Galliano's Spring/Summer 2000 collection and was credited with attracting a younger demographic to the brand.