The 33-year-old mother-of-two will replace Kate Moss as the brand's celebrity ambassador, and star in Weitzman's Fall 2014 campaign ads.
Weitzman tells Wwd.com, "Gisele (is) such a seasoned professional. She exemplifies the Stuart Weitzman woman with her zest of life, love and family."
Bundchen appears topless in one table-top shot for photographer Mario Testino's campaign.
The model is a busy mum right now - she also sings in new H&M ads and last month (May14) she was unveiled as the latest face of Chanel No. 5.
The Brazilian beauty will follow Nicole Kidman as the fragrance firm's latest model and she will appear in a new Tv ad shot by Australian director Baz Luhrmann.