Knightley was born in Teddington, London, England, the daughter of Sharman MacDonald, an award-winning playwright, and Will Knightley, a theatre and television actor.Her father is English and her Scottish mother is of half Welsh ancestry. She has an older brother, Caleb. Knightley lived in Richmond, attending Stanley Junior School, Teddington School and Esher College. She was diagnosed with dyslexia at the age of six, but nevertheless was successful in school and was thus permitted to acquire a talent agent and pursue an acting career. She requested an agent as early as the age of three and got one when she turned six, from her mother as a reward for studying hard. Knightley has noted that she was "single-minded about acting" during her childhood. She performed in a number of local amateur productions, including After Juliet (written by her mother) and United States (written by her then drama teacher, Ian McShane, no relation to the actor).Keira Knightley appeared in several television films in the mid to late 1990s—as well as ITV1's The Bill—before being cast as Sabé, Padmé Amidala's decoy, in the 1999 science fiction blockbuster Star Wars Episode I: The Phantom Menace. Sabé's dialogue was dubbed over with Natalie Portman's voice. This was to hide the fact that the handmaiden Padmé (played by Natalie Portman) was actually disclosed as the real Queen Amidala at the end of the film. Knightley was cast in the role due to her close resemblance to Portman; even the two actresses' mothers had difficulty telling their daughters apart when the girls were in full makeup. Knightley's first starring role followed in 2001, when she played the daughter of Robin Hood in the made-for-television Walt Disney Productions feature, Princess of Thieves. During this time, Knightley also appeared in The Hole, a thriller that received a direct-to-video release in the United States. She appeared in a miniseries adaptation of Doctor Zhivago that first aired in 2002 to mixed reviews but high ratings. Knightley's breakthrough role was in the football-themed film, Bend It Like Beckham, which was a success in its August 2002 UK release, grossing $18 million, and in its March 2003 U.S. release, grossing $32 million.After Bend It Like Beckham's UK release raised her profile, she was cast in the big budget action film, Pirates of the Caribbean: The Curse of the Black Pearl (along with Orlando Bloom and Johnny Depp) which was produced by Jerry Bruckheimer and opened in July 2003 to positive reviews and high box office grosses, becoming one of the biggest hits of summer 2003 and cementing Knightley as the new "It" girl.
Knightley had a role in the British romantic comedy Love Actually, which opened in November 2003. Her next film, King Arthur, opened in July 2004 to negative review however in preparation for the role she took fighting and horseback-riding lessons. In the same month, Knightley was voted by readers of Hello! magazine as the film industry's most promising teen star. Additionally, TIME magazine noted in a 2004 feature that Knightley seemed dedicated to developing herself as a serious actress rather than a film star. She appeared in three films in 2005, the first of which was The Jacket, alongside Adrien Brody. She next appeared in Tony Scott's Domino, an action film based on the life of bounty hunter Domino Harvey. The film has been Knightley's greatest critical flop to date. Knightley's critics often suggested she was nothing more than a pretty face, which led the young starlet to comment to Elle magazine, "I always feel like I’m the one with everything to prove."Pride & Prejudice rounded out 2005. Variety wrote about her portrayal of Elizabeth Bennet: "Looking every bit a star, Knightley, who's shown more spirit than acting smarts so far in her career, really steps up to the plate here, holding her own against the more classically trained Matthew Macfadyen, as well as vets like Brenda Blethyn, Donald Sutherland, Penelope Wilton, and Judi Dench with a luminous strength that recalls a young Audrey Hepburn. More than the older Jennifer Ehle in the TV series, she catches Elizabeth's essential skittishness and youthful braggadocio, making her final conversion all the more moving." The film grossed more than $100 million worldwide, and Knightley earned a Golden Globe nomination and an Oscar nomination (the Oscar ultimately went to Reese Witherspoon). The Academy Award nomination made her the third-youngest performer ever nominated. BAFTA's decision not to nominate her drew criticism from Pride & Prejudice producer Tim Bevan.