Thor is a 2011 American superhero film based on comic book character of the same name published by Marvel Comics and is the fourth film released in the Marvel Cinematic Universe. The film was released on April 21, 2011 in Australia and April 27, 2011 in the UK. It is scheduled for release on May 6, 2011 in the United States and April 29 in Mexico. Thor was also released in 3-D and IMAX 3D. The film stars Chris Hemsworth, Natalie Portman, Tom Hiddleston, Anthony Hopkins, and Stellan Skarsgård with Kenneth Branagh directing a script by Ashley Edward Miller, Zack Stentz, and Don Payne.
The project of a film adaptation of Thor was in "development hell" for several years before Marvel Studios signed Protosevich to write its script in 2006. Matthew Vaughn was to direct the film in late 2008 for a release in 2010. Branagh replaced Vaughn in late 2008, and the film's release was rescheduled into 2011. The main characters were cast in 2009, and principal photography took place from January to May 2010.