She joins British actress Kate Winslet and French actress Juliette Binoche who are also signed up to the Lancôme.
Lancôme International president Youcef Nabi says: “By her remarkable personality and career, Julia Roberts is an emblematic woman of her time. Her exceptional talent, her radiance and her strong commitments perfectly echo Lancôme’s values. We are convinced she will embody the brand in the most sublime way possible”.
The Pretty Woman actress is one of Hollywood’s highest paid actresses and has starred in Erin Brockovich and Notting Hill. Her upcoming films for 2010 include Eat, Pray, Love and Valentine’s Day alongside Anne Hathaway Jessica Alba and Ashton Kutcher.
The skin, haircare and cosmetic brand is owned by the L’Oreal group.
Earlier this year, L’Oreal signed up Girls Aloud singer and The X Factor judge Cheryl Cole as a brand ambassador in a one-year deal.