John Cargill Thompson was a Scottish dramatist specialising in one-person plays. After the performance of his 52nd play, he was described as "Britain's most prolific playwright", surpassing Shakespeare's 37 and Alan Ayckbourn's 51.
He was born in Burma, but brought up in Glasgow. He was educated at Glasgow High School and the Royal Scottish Academy of Music and Drama. He taught in the Drama Department of University College of North Wales, Bangor, and was senior lecturer in acting at the School of Theatre, Manchester Polytechnic, before giving up teaching to write full-time.
Many of his plays were based on the 18th-century dramatists and actors about whom he had taught. He had several successes at the Edinburgh Festival Fringe, notably a double Fringe First Award in 1992 for Shylock Triumphant, about Charles Macklin and Every Inch a King about David Garrick. His record-breaking 52nd play was Soul Doubt, staged at the New End Theatre, Hampstead, London in 1997.
He collected the works of G.A. Henty and wrote The Boys' Dumas, G.A. Henty: Aspects of Victorian Publishing (1975).