The semi-comical story is about William Fisher, a working-class 19-year-old living with his parents in the fictional town of Stradhoughton in Yorkshire.
Bored by his job as a lowly clerk for an undertaker, Billy spends his time indulging in fantasies and dreams of life in the big city as a comedy writer.
Other regular cast members included Pamela Vezey as Alice, Colin Jeavons as Shadrack, May Warden as Billy's grandmother, and Sally Watts as Barbara.
The book was by well-known British sitcom writers Dick Clement and Ian La Frenais, and the music and lyrics were by film composer John Barry and Don Black respectively.
An American adaptation entitled Billy and starring Steve Guttenberg, Peggy Pope, and James Gallery aired briefly on CBS in 1979.