The Demon Headmaster is a British television series based on the children's books by Gillian Cross of the same name. Made for CBBC, the drama was first broadcast between 1996 and 1998. The first series contained six episodes, and aired twice weekly from 2 to 18 January 1996, the second series contained seven episodes and aired weekly from 25 September to 6 November 1996, and the third series contained six episodes and aired twice weekly from 6 to 22 January 1998.

School location scenes in the first series were filmed at Hatch End High School, in Hatch End, Harrow, North West London and The Royal Masonic School for Girls in Rickmansworth, Hertfordshire. Other scenes were filmed around West London, and the Vulcan Tower is in fact the building for Atrium in Uxbridge. CGI was used to make this building appear on a traffic island close to Warwick Avenue. Some scenes in the later series were filmed in the village of Sarratt, Hertfordshire and other locations in Hertfordshire and Buckinghamshire.

A direct sequel of the original series began airing on CBBC from 14 October 2019, with Nicholas Gleaves playing the titular character. It was confirmed on BBC Breakfast that this series was a continuation of the original.