Matthew Waterhouse (born 19 December 1961) is an English actor and writer known for his role as Adric in the BBC science fiction television series Doctor Who from 1980 to 1982.
Waterhouse was born in Hertford, but brought up in Haywards Heath, Sussex. The son of a solicitor, he was educated at St. Wilfrid's Primary School, West Sussex and Shoreham Grammar School. Waterhouse was a great fan of Doctor Who in his younger days, claiming that he was "obsessed" with the show.
Adric was a companion of Tom Baker and Peter Davison's Doctors from 1980 to 1982. Waterhouse was the youngest actor to play a companion and Doctor Who was only his second professional acting role. He played the schoolboy Briarley in the BBC2 adaptation of To Serve Them All My Days with John Duttine, and it was only shortly before he filmed his appearance on the miniseries that he found out he had secured the role of Adric.