The filing in Los Angeles Superior Court came after media reports earlier this week that the couple had separated.
Fox, 29, is best known for starring in the blockbuster "Transformers" movie in 2007 and a 2009 sequel. In 2008 she was named the world's sexiest woman in a poll by the magazine FHM.
She has said she met Austin Green, who appeared in the 1990s television show "Beverly Hills, 90210," when she was 18 and he was 30. They went on to date for years and married in 2010.The couple have two children together.