Theron received critical acclaim for her portrayal of serial killer Aileen Wuornosin Monster (2003), for which she won the Academy Award, Silver Bear, Golden Globe Award and Screen Actors Guild Award for Best Actress among several other accolades, becoming the first South African to win an Academy Award in a major acting category. She received further Academy Award and Golden Globe Award nominations for her performance in the sexual harassment-themed drama North Country in 2005 and a Golden Globe Award nomination for her performance in Jason Reitman's 2011 film Young Adult.
Theron became a U.S. citizen in 2007, while retaining her South African citizenship. In the late 2000s, she moved into the field of producing, both in television and film. In 2006, she produced the documentary East of Havana. She had producing credits on the films The Burning JF MAGAZINE!