Schiffer said that she was popular in high school, but felt socially overshadowed by the other girls in her class. She has revealed that because she was so tall, she became very shy and did not want to be noticed. She was also subjected to jealousy by others as she came from a wealthy family that was well-known locally. Schiffer became fluent in French and English.
She originally wanted to become a lawyer and work in her father's law firm. She later dropped these aspirations when in October 1987 at seventeen she was spotted in a nightclub in Düsseldorf by Michel Levaton, the boss of Metropolitan Model Agency who signed her up to become a model.
In the early 1990s she starred in highly publicised Guess? jeans adverts in North America which created essential publicity for Schiffer. Paul Marciano said in E! Forbes Top 15 Supermodel Beauties Who Made Bank, "Guess name became really much more known around the world because [of] Claudia". Soon after appearing in the campaigns, her name was launched worldwide, appearing on five magazine covers in the United States and seven covers around Europe. Her modelling career continued to grow. Schiffer joined Thomas Zeumer's prestigious Metropolitan Models and was contracted to model for Revlon. She also became deeply involved in modelling for several catalogues and modelled on high profile catwalk shows. Schiffer has done catwalk modelling for Versace, Jil Sander, Dolce & Gabbana, Ralph Lauren and Valentino. Vanity Fair, Rolling Stone, The New York Times and People all saw Schiffer as the first model to make their covers. She has also appeared many times on covers of Vogue, Harper's Bazaar, Cosmopolitan and Time. Schiffer was the first model who worn the first fantasy bra by Victoria's Secret.
Schiffer has also been the face of Mango, a chain of Spanish clothes stores and Accessorize, where she had her ears pierced especially for her Autumn/Winter 2006 Accessorize advertising campaign in 2006. Schiffer still holds a contract with L'Oréal and Ebel watches, and her billboard picture for Kenar has also hung over millions of tourists at Times Square. Since 1990, she has created a swimsuit calendar each year which she stars in and designs herself.
Schiffer later secured contracts with Pepsi appearing in advertisements promoting the brand, and has also danced with a cartoon version of Mickey Mouse in advertisements promoting Fanta for an estimated $2 million. From her appearances in a 1998 Citroën advertisement, she earned a reputed £3 million. She appeared nude in the advert, but as she was posed behind the car, only her feet and from her shoulders up were visible, and she did not know how to drive at the time. Karl Lagerfeld recently filmed her for a Dom Perignon campaign, some ten years after her first appearances in Chanel adverts.
She is signed to several agencies, including 1/One Management in New York City and her mother agency 'Model Management' in Hamburg.
Schiffer has appeared on several talk shows and sitcoms, such as Larry King Live, The Late Show with David Letterman, Late Night with Conan O'Brien, Dharma & Greg and Arrested Development. She was also in boyband Westlife's music video for "Uptown Girl", and made a cameo in Bon Jovi's video for "Say it isn't so".
She has also released four exercise videos, entitled Claudia Schiffer's Perfectly Fit, which were successful and reached the bestsellers list. Schiffer has hosted the French Fashion Awards and the World Music Awards in Monaco.
With fellow supermodels Christy Turlington, Naomi Campbell, and Elle Macpherson, Schiffer was joint owner of a chain of fashionable restaurants called the Fashion Café in 1995. Schiffer remains a prominent figure in German society and helped present and carry the trophy with Pelé during opening ceremonies at the 2006 World Cup. She also presented Prince William with a polo trophy in 2002.
When talking about the model profession at present, she said: "Supermodels, like we once were, don't exist any more." She has said that Gisele Bündchen is the only person who comes close to earning the supermodel title.
On 25 May 2002, she married the film producer Matthew Vaughn. Instead of an engagement ring, Vaughn bought her a tortoise. On her wedding day, many journalists and 200 onlookers gathered to see her in her wedding dress. She was married in St. George's church in the village of Shimpling. The wedding reception was held at Schiffer's Elizabethan mansion.
Schiffer and Vaughn have two children: son Caspar Matthew, (born 30 January 2003) and daughter Clementine de Vere Drummond, (born 11 November 2004). They all now live in London. During spare time, Schiffer enjoys horse riding, painting, playing tennis and skiing.
Schiffer had two significant problems with harassment in the past. In 2002, an Italian kitchen porter, named Agostino Pomata, was arrested after making nine visits to Schiffer's £5 million Suffolk mansion near Bury St Edmunds, attempting to see her. Charges against Agostino Pomata were dropped however, as he was sectioned under the Mental Health Act. He had believed that the Pope had told him to marry Schiffer. Then later in 2004, Louis Brisette a Canadian man, was accused of harassing Schiffer, again at her mansion in Suffolk. He reportedly called at her mansion three times in total in the hope of seeing Schiffer. He also repeatedly left letters at her home.