In 2001 Post-9/11, Gisele appeared with model Carolyn Murphy and actress Julianne Moore in print ads for the CFDA Fashion for America T-shirt campaign benefiting the Twin Towers Fund. In December she Posed with her teacup Yorkie, Vida, wearing the fund-raising tee on Vogue’s cover.
Bündchen lends her support and image to a number of charities and humanitarian causes, such as the I am African campaign, in which she painted her face to protest the lack of attention given to Africa's HIV/AIDS victims. Without receiving payment, Bündchen was, in 2006, the face of American Express Red Card, an initiative launched by U2 front man Bono and Bobby Shriver to send a percentage of monies earned from the financial transactions of this credit card to Africa's HIV/AIDS victims.
In 2009, she appeared almost simultaneously in 30 covers of the international issues of Elle magazines wearing (Product) Red clothing and posing with products from companies who support the same cause.
In 2003, Bündchen designed an exclusive and limited edition of platinum hearts, working with Platinum Guild International and Harper’s Bazaar, crafted by jewelers Gumuchian Fils. These platinum hearts were sold to raise money for St. Jude Children's Research Hospital which specializes in cancer treatment. She served as the spokesperson and campaign model for Fashion Targets Breast Cancer. Bündchen already gave a São Paulo Fashion Week's payment check for Zero Hunger (in Portuguese: Fome Zero), a Brazilian-government program introduced by Brazilian president Luiz Inácio Lula da Silva also in 2003.
She was, in 2009, one of the celebrities to sign up for the auction fundraiser of celebrities autographed iPods to raise cash for the victims of Hurricane Katrina, organised by Tonic.com.. The money is for the Music Rising institution which aims to recover and invest in the musical culture of the destroyed areas.
She promotes protecting the Brazilian Atlantic Forest and Amazon Rainforest water sources, donating to this cause a percentage of profits from her line of sandals named Ipanema Gisele Bündchen. Also, Bündchen helps projects such as Nascentes do Brasil, ISA, Y Ikatu Xingu and De Olho nos Mananciais. Bündchen and Grendene, the company that produces and disseminates her line of sandals, also joined the Florestas do Futuro project for the reforestation of the Brazilian Atlantic Forest. The project was created by the NGO named SOS Atlantic Forest in 2004. The new forest, named for Grendene – Gisele Bündchen, started with 25,500 shoots of 100 different species, enough to revitalize an area of 15 hectares.
In 2008 she Launches Projeto Água Limpa (Clean Water Project), aimed at sustainable environmental management in her home state of Rio Grande do Sul.
On 20 September 2009, she was designated Goodwill Ambassador for the United Nations Environment Programme (UNEP).
In January 2010, Bündchen donated US$1,500,000 to relief efforts for the 2010 Haiti earthquake.
Since 2010, she worked on an animated web series called Gisele and the Green Team, to highlight green issues to educate kids and adults.
In March 2011, it was reported, Bundchen wrote a check for $1 million to the earthquake fund created by the Japanese Red Cross Society after Japan was struck by the most powerful earthquake to hit the island nation in recorded history and the tsunami it unleashed. It was also reported she sent $250,000 to the Pacific Tsunami Fund and Save the Children and another $250,000 to a Japanese Red Cross earthquake fund.