Sir Kenneth Charles Branagh (/ˈbrænə/ BRAN-ə; born 10 December 1960) is a British actor and filmmaker. Born in Belfast and raised primarily in Reading, Berkshire, Branagh trained at RADA in London and served as its president from 2015 to 2024. His accolades include an Academy Award, four BAFTAs, two Emmy Awards, a Golden Globe Award, and an Olivier Award. He was appointed a Knight Bachelor in 2012, and was given Freedom of the City in his native Belfast in 2018. In 2020, he was ranked in 20th place on The Irish Times's list of Ireland's greatest film actors.

Branagh has directed and starred in several film adaptations of William Shakespeare's plays, including Henry V (1989), Much Ado About Nothing (1993), Othello (1995), Hamlet (1996), and As You Like It (2006). He was nominated for Academy Awards for Best Actor and Best Director for Henry V, and Best Adapted Screenplay for Hamlet. He directed Swan Song (1992), which earned a nomination for the Academy Award for Best Live Action Short Film. He also directed Dead Again (1991), Peter's Friends (1992), Mary Shelley's Frankenstein (1994), Thor (2011), and Cinderella (2015). For his semi-autobiographical film Belfast (2021), he was nominated for the Academy Awards for Best Picture and Best Director, and won Best Original Screenplay.

Branagh directed and starred as Hercule Poirot in the eponymous film series (2017–present). He has also acted in Celebrity (1998), Wild Wild West (1999), The Road to El Dorado (2000), Harry Potter and the Chamber of Secrets (2002), and Valkyrie (2008). His portrayal of Laurence Olivier in My Week with Marilyn (2011) earned him a nomination for the Academy Award for Best Supporting Actor. He played supporting roles in Christopher Nolan's films Dunkirk (2017), Tenet (2020), and Oppenheimer (2023).

Branagh has starred in the BBC1 series Fortunes of War (1987), the Channel 4 series Shackleton (2002), the television film Warm Springs (2005), and the BBC One series Wallander (2008–2016). He received a Primetime Emmy Award and an International Emmy Award for Best Actor for his portrayal of SS leader Reinhard Heydrich in the HBO film Conspiracy (2001).

Kenneth Charles Branagh was born in Belfast on 10 December 1960, the son of working-class Protestant parents Frances (née Harper) and William Branagh. His father was a plumber and joiner who ran a company that specialised in fitting partitions and suspended ceilings. He is the middle of three children, with an older brother and a younger sister, and lived in the Tigers Bay area of Belfast. He was educated at Grove Primary School. In early 1970, at the age of nine, Branagh moved with his family to England to escape the Troubles; they settled in Berkshire, where Branagh grew up in Reading and attended Whiteknights Primary School and Meadway School in Tilehurst. He appeared in school productions such as Toad of Toad Hall and Oh, What a Lovely War!

At school, Branagh learned to speak with an RP accent to avoid bullying. Discussing his identity, he later said, "I feel Irish. I don't think you can take Belfast out of the boy." He also attributes his "love of words" to his Irish heritage. He attended the amateur Reading Cine & Video Society (now called Reading Film & Video Makers) and was a keen member of Progress Theatre, of which he is now the patron. After disappointing A-level results in English, history, and sociology, he went on to train at the Royal Academy of Dramatic Art in London. In 1980, RADA's principal Hugh Cruttwell asked Branagh to perform a soliloquy from Hamlet for Queen Elizabeth II during one of her visits to the academy.

Branagh's first film appearance was as an uncredited role as a Cambridge student in the sports drama Chariots of Fire (1981). Branagh achieved early success in his native Northern Ireland for his role as Billy, the title character in the BBC's Play for Today trilogy known as the Billy Plays (1982–84), written by Graham Reid and set in Belfast. He received acclaim in the UK for his stage performances, first winning the 1982 SWET Award for Best Newcomer, for his role as Judd in Julian Mitchell's Another Country, after leaving RADA. Branagh was part of the new wave of actors to emerge from the academy. Others included Jonathan Pryce, Juliet Stevenson, Alan Rickman, Anton Lesser, Bruce Payne and Fiona Shaw. In 1984, he appeared in the Royal Shakespeare Company production of Henry V, directed by Adrian Noble. The production played to sold-out audiences, especially at the Barbican in the City of London. It was this production that he adapted for the film version of the play in 1989. He and David Parfitt founded the Renaissance Theatre Company in 1987, following success with several productions on the London Fringe, including Branagh's full-scale production of Romeo and Juliet at the Lyric Studio, co-starring with Samantha Bond.

The first major Renaissance production was Branagh's Christmas 1987 staging of Twelfth Night at Riverside Studios in Hammersmith, starring Richard Briers as Malvolio and Frances Barber as Viola, and with an original score by actor, musician, and composer Patrick Doyle, who two years later was to compose the music for Branagh's film adaptation of Henry V. This Twelfth Night was later adapted for television. The company's debut season also included Public Enemy, a play written by Branagh set in his native Belfast. Also in 1987, Branagh found his first leading film role as James Moon in the British film adaptation of J.L. Carr's book A Month in The Country. Here he plays a homosexual ex-army officer who, following the war, has taken on a job to excavate a burial in the churchyard. He instead spends most of his time looking for Saxon treasures. The film is set in a 1920s rural Yorkshire village, where Branagh’s character meets a character played by Colin Firth, also in his first major role.