Lena Headey (/ˈliːnə ˈhiːdi/ LEE-nə HEE-dee; born 3 October 1973) is an English actress, best known for playing Cersei Lannister in HBO's series Game of Thrones.

After being scouted at age 17, she worked steadily as an actress in small and supporting roles in films throughout the 1990s, before finding fame for her lead performances in big-budget films such as the fantasy film The Brothers Grimm (2005), in which she acted opposite Matt Damon and Heath Ledger, the action film 300 (2007), portraying the role of Gorgo, Queen of Sparta, and the adventure and biographical feature The Red Baron (2008).