Keith Howell Charles Allen was born on 2 September 1953 in Gorseinon, near Swansea, Wales — though an older source instead names nearby Llanelli, where his mother's family lived. His father, Edward Charles Owen, was a Royal Navy petty officer submariner, and his mother was a Welsh waitress. He spent his early years near Swansea and in Malta before the family settled in Gosport, Hampshire, while his father was based at Portsmouth.
At the age of eleven, when his father was posted to Singapore, Allen was sent to boarding school in Essex. He later attended a comprehensive school in Swansea and spent a period in borstal, before earning enough O-levels to gain a place at the Welsh College of Music and Drama, from which he was later expelled after a dispute over car parking. Although he has lived most of his life in England, Allen has stated plainly, 'I am Welsh.'
Allen built a long career across film, television and comedy, becoming one of the breakthrough acts at the Comedy Store in 1979 and a regular performer in Channel 4's 'The Comic Strip Presents...'. His film roles include the lodger in Danny Boyle's 'Shallow Grave' (1994), a drug dealer in 'Trainspotting' (1996), Emrys in the Welsh film 'Twin Town' (1997, directed by his brother Kevin Allen), and the Sheriff of Nottingham in the BBC's 'Robin Hood' (2006-2009). He played convicted killer John Cooper in ITV's 'The Pembrokeshire Murders' (2021) and appeared in the BBC's 'Steeltown Murders' (2023).
Allen is the father of singer Lily Allen and actor Alfie Allen, and the older brother of actor and director Kevin Allen. With his band Fat Les, he co-wrote England's 1990 World Cup song 'World in Motion' and the football anthem 'Vindaloo'.