Gisele Caroline Nonnenmacher Bün (born July 20, 1980) is a Brazilian supermodel.. According to Forbes, she is currently the sixteenth richest woman in the entertainment world, having earned $33 million in 2007, adding to her estimated $150 million fortune. She is currently listed in the Guinness Book of World Records as the "world's richest supermodel".

Originally, Bün wanted to be a professional volleyball player and considered playing for the Brazilian team, Sogipa. While in school, Bün was so thin that her friends used to call her "Olía Palito" (Portuguese for Olive Oyl, Popeye's skinny girlfriend), and "Saracura" (a type of Brazilian shorebird).

In 1993, a then-13-year-old Bün joined a modeling course with her sisters Patría and Gabriela at her mother's insistence. The course, instructed by Dilson Stein, was designed for teenagers aspiring to become models. The following year, Stein took Bün, along with some other girls to SãPaulo to give them an opportunity to walk in a big city and to be evaluated by Brazilian Elite agents. 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. Bün placed fourth in the world contest, held in Ibiza, Spain. In 1996, Bün 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 was the fourth model in history to grace the cover of Rolling Stone magazine, when she was named "the most beautiful girl in the world". Bün 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 also been featured in broader market publications such as Time, Vanity Fair, Forbes, Newsweek, Veja, totaling almost 500 magazine covers throughout the world.

Bün consistently works with acclaimed photographers such as Nino Muñ Mario Testino, Steven Meisel, Nick Knight, Mert and Marcus, Rankin, Annie Leibovitz, Karl Lagerfeld, Peter Lindbergh, Mario Sorrenti and Patrick Demarchelier, among others, and directors such as Jean Baptiste Mondino and Bruno Aveillan.

According to Claudia Schiffer: "Supermodels, like we once were, don't exist any more." and reckons that Gisele Bün is the only one who comes close to earning the supermodel title.