Ross met Mario Testino on Portobello Road in London, where he asked her and a group of friends to do a shoot for British Vogue. She worked sporadically as a model throughout her childhood. She appeared on Ozzy Osbourne’s No Rest for the Wicked album cover at the age of nine. In 1992, she signed with Storm Management.

In 2000, Ross became the face of an Emanuel Ungaro ad campaign. In May, Ross appeared on the twentieth anniversary cover of The Face alongside Kate Moss. In June, Ross appeared on the cover of British Vogue, shot by personal friend Mario Testino. Ross was then awarded Model of the Year at the Elle Style Awards.

Ross was photographed by Robin Derrick for the December 2000/January 2001 issue of Vogue Russia. In 2002, Ross shot Burberry’s spring campaign alongside Kate Moss and Eva Herzigova. In January 2002, Ross was again featured on the cover of British Vogue, also photographed by Testino, alongside nine other British models including Kate Moss, Naomi Campbell, Stella Tennant and Erin O’Connor. Ross also appeared on the November 2002 cover of British magazine i-D, photographed by Kayt Jones.

Ross married director Rupert Sanders in 2002. Though both Ross and Sanders are British, they moved to Los Angeles to further Sanders’ career, and Ross focused on being a wife and mother. Together they have two children, daughter Skyla and son Tennyson. In July 2012, Us Weekly published photos of Sanders cheating on Ross with actress Kristen Stewart, prompting Sanders and Stewart to issue separate public apologies. Ross subsequently filed for divorce from Sanders in January 2013, seeking joint custody, spousal support, and legal fees. The divorce was finalised on 30 May 2014.

In 2003, Ross became the face of the luxury footwear brand Jimmy Choo. She also modelled for the cover of Vogue Russia, photographed by Todd Barry.

In 2004, she modelled for Dior’s Addict perfume. Ross then appeared in the Pirelli Calendar, photographed by Nick Knight. Shortly after, Ross began a three-year hiatus to focus on her family life that ended in 2007 when she re-signed with Storm.

Following her husband’s well publicised affair, Ross began to stage a career comeback, appearing on the cover of online magazine The Edit and in the pages of Vanity Fair. Ross made her runway return in September 2012, walking for Alexander Wang at New York Fashion Week.

In 2014, Ross was invited to design a capsule collection for Genetic Denim which was sold exclusively at Net-a-Porter.

In 2014, Ross confirmed she was dating record producer Jimmy Iovine. They married on Valentine’s Day, 2016, in California at the home of music producer David Geffen.