Brazilian model Fontana was born in Curitiba, Paraná, Brazil. In 1996 she made it to the finals of the Elite Model Look when she was just 13 and in the following year she moved from South Brazil to Milan, Italy.
She was married to model Álvaro Jacomossi but they divorced in 2004. Their son, Zion, was born in 2003. Fontana married actor and model Henri Castelli on December 10, 2005 and their son, Lucas, was born on October 23, 2006 in São Paulo. Fontana and Castelli divorced in 2007. She was engaged to Rohan Marley but the engagement ended in September 2012.