Rosamund Mary Ellen Pike (born 27 January 1979) is an English actress who began her acting career by appearing in stage productions such as Romeo and Juliet and Skylight. After her screen debut in the television film A Rather English Marriage (1998) and television roles in Wives and Daughters (1999) and Love in a Cold Climate (2001), she received international recognition for her film debut as Bond girl Miranda Frost in Die Another Day (2002), for which she received the Empire Award for Best Newcomer. Following her breakthrough, she won the BIFA Award for Best Supporting Actress for The Libertine (2004) and portrayed Jane Bennet in Pride & Prejudice (2005).

Pike had film appearances in the sci-fi film Doom (2005), the crime-mystery thriller film Fracture (2007), the drama film Fugitive Pieces (2007), the coming-of-age drama An Education (2009), for which she was nominated for the London Film Critics Circle Award for British Supporting Actress of the Year, and sci-fi comedy The World's End (2013). She also received British Independent Film Award nominations for An Education, Made in Dagenham (2010), and was nominated for a Genie Award for Barney's Version (2010). Her other films include the spy action comedy Johnny English Reborn (2011), the epic action-adventure fantasy Wrath of the Titans (2012) and the action thriller Jack Reacher (2012).

In 2014, her performance in the psychological thriller film Gone Girl was met with widespread critical acclaim and she was awarded the Saturn Award for Best Actress and was nominated for the Academy Award for Best Actress, the BAFTA Award for Best Actress in a Leading Role, the Golden Globe Award for Best Actress in a Motion Picture – Drama, and the Screen Actors Guild Award for Outstanding Performance by a Female Actor in a Leading Role. Pike received further acclaim for her role as Ruth Williams Khama in the biographical drama A United Kingdom (2016) and is nominated for a Saturn Award for Best Actress for her role in the western Hostiles (2017). Her upcoming films include the thriller Three Seconds and Radioactive, in which she will play Marie Curie.