Gisele was born in the southern Brazilian town of Horizontina. She has five sisters: Raquel, Graziela, Gabriela, Rafaela and her fraternal twin Patrícia (who was born five minutes after Gisele). She originally wanted to be a professional volleyball player and had considered becoming a member for the Brazilian team, Sogipa. She was already 170 cm when she was 13. Her friends, in school, used to call her "Olívia Palito" (Portuguese for Olive Oyl, Popeye's skinny girlfriend), and "Saracura" (a Brazilian type of shorebird). Her "discovery" took place at the age fourteen on a school trip to São Paulo while eating a Big Mac when she was scouted by a modeling agent.

A year before that her sisters Patrícia and Gabriela and she had taken a model course instructed by Dilson Stein, to correct their posture, at their mother's insistence. This course was designed for teenagers aspiring to become models. In 1994, Stein took Gisele and other girls to São Paulo to give them an opportunity to walk in a big city and to be evaluated by Brazilian Elite agents. Gisele was selected by them for a national contest, in which she came in second. Later in Ibiza, Spain, Gisele came in fourth in the world contest.

In 1996 Gisele moved to New York City to begin her modeling career, debuting at Fashion Week. Since then, her image has been featured in a variety of advertising campaigns including several seasons for Dior, Balenciaga, Dolce & Gabbana, Missoni, Versace, Céline, Givenchy, Bulgari, Lanvin, Guerlain, Valentino, Ralph Lauren, Earl Jean, Zara, Chloé, Michael Kors, and Louis Vuitton. Gisele represents several Brazilian brands such as Vivo, C&A, Multiplan, Colcci and Credicard.

Grendene has put out her own line of sandals, called Ipanema Gisele Bündchen, which have sold more than 100 million pairs since 2001.

Along with winning the VH1/Vogue Model of the Year award in 1999, she co-hosted the ceremony in 2000 along with actor Cuba Gooding, Jr.. Vogue. In 2000 she was only the fourth model to appear on the cover of Rolling Stone magazine, at which time she was named "the most beautiful girl in the world".

One of Gisele's best moves was in 2000, when she signed a multiyear deal with Victoria's Secret. Her contract is reported to be the highest paid in the fashion industry, and generates $5 million dollars a year, plus a percentage of the sales from the products that she represents. Victoria's Secret considers every single penny invested in her to be good value, because their sales have increased dramatically.

Gisele has appeared on the cover and in many magazines internationally, including: (American Vogue, Italian, British, French, Brazilian, Japanese, Chinese, Korean, Russian, Portuguese, and Spanish editions); ELLE; Allure; The Face; Arena (magazine); Flare; Rolling Stone; Time; Vanity Fair; Forbes; Newsweek; Esquire; Veja; Caras; GQ and Marie Claire.

On August 2006, Gisele told Italian daily Corriere della Sera, that she will be retiring from modeling. “Enough, it's over. It's the end when it comes to catwalks.” She also said, "I'm very tired of going from one stylist to another, running here and there - your cell phone's always ringing and someone's always fussing over you with a blow dryer.”

Gisele's rise to fame has not come without controversy. Like Heidi Klum and several other models, she moved from her original agency Elite to IMG. John Casablancas, head of Elite models, accused Bündchen of being a stoner who slept her way to the top, though he now claims he was misquoted. He also filed a $15 million lawsuit against her.

Gisele has also been forced to defend the naturalness of her figure. At home the press calls her the "Boobs from Brazil." One newspaper report blamed her for the 36,000 breast enhancements in Brazil in 2000. She says that all the women of her family have big breasts.

In 2002, during the taping of the annual Victoria's Secret Fashion Show, Gisele was the target of a protest made by four female members of PETA - People for the Ethical Treatment of Animals - because she was signed to be the new face of fur designer company Blackglama famous campaign "What Makes a Legend Most?". When Gisele was on the stage, four women jumped into the runway holding posters that read "Gisele: Fur Scum" and included the logo for PETA. Gisele tried to ignore them and keep the show while several secutiry guards detained the protestors.

After the incident, the producers decided to stop the music and redid Gisele's segment after the protesters were removed. Gisele came back and was hugely applauded by the audience and on the next day she made headlines all over the globe.

When she is not working or traveling the world, Gisele enjoys spending time with her family, friends and her dog Vida (meaning "life" in Portuguese), a Yorkshire terrier. Her first boyfriend in the United States was model Scott Barnhill, but they dated for only six months. After Scott she was also linked with hotel tycoon Vikram Chatwal and Josh Hartnett, but she never confirmed the rumors about these two.

In one of her trips to Brazil, for a fashion show, she meet João Paulo Diniz, a Brazilian billionaire. They were photographed kissing each other by the paparazzi but once again she broke-up with him when she came back to New York.

But Gisele's most notorious romance is her on/off relationship with Titanic star Leonardo DiCaprio. They met in 2000 during a fashion party in Los Angeles. On the next day Leo sent flowers to Gisele and invited her to dinner, but she refused. A month later he finally had the opportunity to take her on a date, and since then Gisele and Leo started to date and became one of the most famous and intriguing couples in the world, but their first public appearance was only in 2005, on the 77th Annual Academy Awards. In 2004, she and her boyfriend, Leonardo DiCaprio, visited the Xingu, one of the biggest Brazilian tribes of Indians. The visit was made almost anonymously.

In November of 2005 they broke-up and after a little while Leo started a new relationship with Israeli model Bar Refaeli. Gisele was also linked with Fantastic Four actor Chris Evans. But in July of 2006 they were spotted leaving a restaurant in West Hollywood after a birthday party to Gisele. In the next few days, Gisele was photographed in Malibu with Leo's mom, Irmalin and his stepbrother, Adam Farrar. However, Gisele has denied that she is currently seeing anyone.

Speaks Portuguese as her native language, as well as English as her second language.

Of a film career, Gisele said "I think it would be interesting," but counters "I'm young and I like what I do for now and I understand that everything in life happens for the moment."

She made her movie debut in 2004 comedy Taxi as Vanessa, with Queen Latifah and Jimmy Fallon. Following the film appearance, she received more film offers, but chose to concentrate on her successful career. She also made an appearance on 2006 hit comedy The Devil Wears Prada, playing the character Serena, Meryl Streep's assistant.