Matthew Robert Smith (born 28 October 1982) is an English actor. He is known for playing the Eleventh Doctor in the BBC science fiction television series Doctor Who (2010–2013), Prince Philip in Netflix's historical series The Crown (2016–2017)—for which he received a Primetime Emmy Award nomination—and Daemon Targaryen in HBO's fantasy drama series House of the Dragon (2022–present).

Smith initially aspired to be a professional footballer, but spondylolysis forced him out of the sport. After joining the National Youth Theatre and studying drama and creative writing at the University of East Anglia, he became an actor in 2003, performing in plays including Murder in the Cathedral, Fresh Kills, The History Boys and On the Shore of the Wide World in London theatres. Extending his repertoire into West End theatre, he has since performed in the stage adaptation of Swimming with Sharks with Christian Slater, followed a year later by a critically acclaimed performance in That Face.

Smith's first television role came in 2006 as Jim Taylor in the BBC adaptations of Philip Pullman's The Ruby in the Smoke and The Shadow in the North, while his first major role in television came as Danny in the 2007 BBC series Party Animals. In film, he has played the physical forms of Skynet in the sci-fi action film Terminator Genisys (2015), a 1960s pimp in the psychological horror film Last Night in Soho (2021), Milo Morbius in the superhero film Morbius (2022), and as a 90s punk in the Darren Aronofsky crime thriller Caught Stealing (2025).

Matthew Robert Smith was born in Northampton, England on 28 October 1982, the son of Lynne and David Smith. He has an elder sister named Laura Jayne, who was one of the dancers featured in the music video for Eric Prydz's 2004 song "Call on Me". Smith attended Northampton School for Boys. His grandfather had played football for Notts County and Smith had also planned to play football, having played for the youth teams of Northampton Town, Nottingham Forest, and Leicester City, becoming captain of the latter's youth team. A serious back injury resulted in spondylolysis; he was unable to continue with a footballing career.

Smith's drama teacher introduced him to acting by signing him up for theatrical productions without his consent. After Smith failed to participate on the first two occasions, his teacher arranged for him to play the tenth juror in an adaptation of Twelve Angry Men. Although he took part, he refused to attend a drama festival for which his teacher had also signed him up, as he saw himself as a footballer and believed acting would damage his social life. His teacher persisted, eventually persuading him to join the National Youth Theatre in London. After leaving school, Smith studied Drama and Creative Writing at the University of East Anglia, graduating in 2005. With the National Youth Theatre, he played Thomas Becket in Murder in the Cathedral (2003) and Bassoon in The Master and Margarita (2004). His role in the latter earned him an agent and his first professional jobs, Fresh Kills and On the Shore of the Wide World, which led him to seek an agreement with his university so that he could graduate without attending lectures in his final year.

Smith's first television role was as Jim Taylor in the BBC adaptations of the Sally Lockhart quartet books The Ruby in the Smoke and The Shadow in the North. His first major television role came in the television series Party Animals, a BBC drama series about fictional parliamentary advisors and researchers. Smith portrayed Danny Foster, a parliamentary researcher who was described as an intelligent but timid "politics geek" who should have moved on from researching at his age. In an interview in 2007, Smith summarised the character as having a romantic outlook of the political world while being cynical elsewhere. He talked about his character's emotional and intellectual maturity; emotionally, he lacks confidence around women, though Smith portrays him as a caring and sensitive but "wry, sarcastic, [and] witty" romantic. Intellectually, Danny is portrayed as attentive and possessing a strong work ethic.

During Smith's tenure in On the Shore of the Wide World, the play transferred to the Royal National Theatre in London. After finishing the play, he took on the role of Lockwood, a pupil in the Alan Bennett play The History Boys. After The History Boys, he acted in the teen play Burn/Chatroom/Citizenship and with Christian Slater in Swimming with Sharks, the latter being his West End début. In 2007, Smith appeared as Henry in the Polly Stenham play That Face at the Royal Court Theatre Upstairs in Chelsea. The play transferred to the Duke of York's Theatre in the West End in 2008 and became Smith's second role there. That Face focuses primarily upon alcohol and drug addiction in an upper-middle-class family after the paternal figure in the family leaves. As Henry, Smith portrayed an aspiring artist who left school to take care of his mother. To prepare for the role, the cast interviewed alcoholics and their families. Smith discussed his character's relationship with his mother in a May 2008 interview with the Evening Standard, saying, "The thing I find tricky to get my head round is why doesn't he just leave? An awful lot of it is co-dependency. ... With Henry there's a real belief—or denial maybe—that he can change his mother. When she is finally pulled away from him to go to rehab, his identity collapses. His sacrifice has been for nothing." The entire cast of the play was nominated for the 2008 Laurence Olivier Award for Outstanding Achievement in an Affiliate Theatre, and Smith garnered an Evening Standard Theatre Award nomination for Best Newcomer for his role. Upon its transfer to the West End, Smith's performance as Henry was highlighted as one of the positive aspects of the play by critics for the Evening Standard, Daily Express, The Guardian and The Times.

Smith auditioned for the role of Will McKenzie in the comedy series The Inbetweeners, with the part eventually being given to comedian and actor Simon Bird. The show's writer Iain Morris said, "We auditioned literally 1000 people [...] He was brilliant - down to the last two for Will, I think. I think he was a bit too dashing!" Smith was cast in Martin McDonagh's black comedy crime In Bruges (2008), as the younger version of Ralph Fiennes' character, but his scenes did not appear in the final cut of the film. He starred in the 2009 short film Together and the film Womb (2010).