The Sea Devils is the third serial of the ninth season of the long-running British science fiction television series Doctor Who, which was first broadcast in six weekly parts on BBC1 from 26 February to 1 April 1972. It was written by Malcolm Hulke and directed by Michael E. Briant. The serial is notable as the first appearance of the Sea Devils and features extensive location filming in cooperation with the Royal Navy, as well as an experimental electronic score by Malcolm Clarke.