John James Osborne was an English playwright, screenwriter, actor, and entrepreneur, regarded as one of the most influential figures in post-war theatre. Born in London, he briefly worked as a journalist before starting out in theatre as a stage manager and actor. He lived in poverty for several years before his third produced play, Look Back in Anger (1956), brought him national fame.

The play, based on Osborne's volatile relationship with his first wife, Pamela Lane, is considered the first work of kitchen sink realism, initiating a movement that used social realism and domestic settings to address disillusionment with British society in the waning years of the Empire. The phrase "angry young man", coined by George Fearon to describe Osborne when promoting the play, came to embody predominantly working class and left-wing writers within this movement. Osborne, often controversial for his left-wing politics, was considered its leading figure, though critics noted a conservative strain even in his early writing.

His other notable works include The Entertainer (1957), Luther (1961), and Inadmissible Evidence (1964), with Luther winning the 1964 Tony Award for Best Play. During this period, Osborne began writing and acting for television and appearing in films, most notably as crime boss Cyril Kinnear in Get Carter (1971).

Osborne's film production ventures included forming Woodfall Film Productions with director Tony Richardson and producer Harry Saltzman in 1958. This company produced several adaptations of kitchen sink realism works, including Osborne-penned adaptations of The Entertainer (1960) and Inadmissible Evidence (1968), and the period comedy Tom Jones (1963), for which he won the Academy Award for Best Adapted Screenplay and the BAFTA Award for Best British Screenplay.

Osborne was married five times, with his first four marriages troubled by affairs and mistreatment. In 1978, he married Helen Dawson, and from 1986 they lived in rural Shropshire. He authored two volumes of autobiography, A Better Class of Person (1981) and Almost a Gentleman (1991), and his non-fiction collection, Damn You, England, was published in 1994. He died from complications of diabetes on 24 December 1994 at the age of 65.