The Demon Headmaster is a British television series based on the children's books by Gillian Cross of the same title. Made by BBC Studios and Sinking Ship Entertainment for CBBC, the drama was first broadcast on 14 October 2019, and is the second adaptation of the books, following the 1996 series. Nicholas Gleaves plays the titular character, a mysterious head teacher with strange powers and dreams of world domination.

The series is a direct sequel of the original series, and features Charlotte Beckett and Sally Oliver as Dinah Hunter and Rose Carter, roles originally portrayed by Frances Amey and Kathryn Wyeth. Amey was approached to reprise the role of Dinah, though no longer acts, whilst Wyeth is based in Wellington, New Zealand. The original Headmaster Terrence Hardiman reprised his role for the revival.

It had been renewed for a second series but was delayed by the COVID-19 pandemic and later cancelled.