Bündchen was born in the Brazilian town of Três de Maio and grew up in Horizontina, Rio Grande do Sul, to Vânia Nonnenmacher, a bank clerk pensioner, and Valdir Bündchen, a university teacher and writer. She has five sisters — Raquel, Graziela, Gabriela, Rafaela and her fraternal twin Patrícia, Gisele's junior by five minutes. In February 2009, she married American football star Tom Brady. Bündchen is Roman Catholic and speaks Portuguese as her native language. She also speaks Spanish and English
I was born in Horizontina, a town in the backcountry of (Brazilian) state Rio Grande do Sul. The town was once mainly colonized by Germans. In the school which I attended, learning German was actually obligatory from third grade on. But being out of touch with the language for such a long time, I unfortunately forgot it. [...] I belong to the sixth generation of my family in Brazil.Originally, Bündchen wanted to be a professional volleyball player and considered playing for the Brazilian team, Sogipa. While in school, Bündchen was so thin that her friends used to call her "Olívia Palito" (Portuguese for Olive Oyl, Popeye's skinny girlfriend) and "Saracura" (a type of Brazilian shorebird).
In 1993, a then-13-year-old Bündchen joined a modeling course with her sisters Patrícia and Gabriela at her mother's insistence. The following year, Bündchen went to São Paulo on a school excursion to give them an opportunity to walk in a big city. In a shopping mall, while eating at McDonald's with her friends, Bündchen was discovered by a modeling agency. She was subsequently selected for a national contest, Elite Look of the Year, in which she placed second — Claudia Menezes, from Bahia, took first place. Bündchen placed fourth in the world contest, held in Ibiza, Spain. In 1996, Bündchen moved to New York City to begin her modeling career, debuting at Fashion Week.
Her debut on the cover of the July 1999 issue of Vogue magazine, and the accompanying editorial entitled "The Return of the Sexy Model", is widely viewed as marking the end of the fashion's "heroin chic" era. She graced the cover again in November and December of that year. She won the VH1/Vogue Model of the Year for 1999, and a January 2000 cover gave her the rare honor of three consecutive Vogue covers. In 2000, she became the fourth model to appear on the cover of the music magazine Rolling Stone, when she was named "the most beautiful girl in the world." Bündchen has been on the covers of many top fashion magazines including W, Harper's Bazaar, ELLE, Allure, international editions of Vogue, as well as style and lifestyle publications such as i-D, The Face, Arena, Citizen K, Flair, GQ, Esquire, and Marie Claire. She has been featured both in the Pirelli Calendar 2001 and 2006 and in broader market publications such as Time, Vanity Fair, Forbes, Newsweek and Veja, more than 500 magazine covers throughout the world.
Bündchen consistently works with acclaimed photographers such as Mario Testino, Steven Meisel, Nick Knight, Mert and Marcus, Rankin, Annie Leibovitz, Karl Lagerfeld, Peter Lindbergh, David LaChapelle, Mario Sorrenti, Nino Munoz and Patrick Demarchelier, and with renowned directors such as Jean Baptiste Mondino and Bruno Aveillan.
Claudia Schiffer said: "Supermodels, like we once were, don't exist any more" and reckoned that Gisele Bündchen was the only one close to earning the supermodel title.
Naomi Campbell said: "Models need to earn their stripes - I just think the term is used a little too loosely. Kate Moss is obviously a supermodel but, after Gisele, I don’t think there’s been one."
On August 26, 2008, the New York Daily News, in a list, named Bündchen the fourth-most-powerful person in the fashion world.
On May 12, 2009, The Independent, called her the biggest star in fashion history.
In 2002, during the taping of the annual Victoria's Secret Fashion Show, Bündchen was the target of a protest made by four members of People for the Ethical Treatment of Animals because she was signed to be the new face of Blackglama, a trademark of a fur-farming cooperative. When Bündchen was on stage, four women jumped onto the runway holding posters that read "Gisele: Fur Scum" and included the logo for PETA. Bündchen tried to ignore them while several security guards detained the protesters. Bündchen told CNN that the protest was "unwarranted" because the fashion show featured only faux fur. After the incident, the producers decided to stop the music and redid Bündchen's segment once the protesters were removed.