Captain Blue is a character in the British Supermarionation television series Captain Scarlet and the Mysterons (1967–68) and its animated remake, New Captain Scarlet (2005). He is a senior officer in the Spectrum Organisation, which is committed to defending Earth against the Mysterons, and is the best friend of Captain Scarlet.

Supermarionation is a style of television and film production employed by British company AP Films in its puppet TV series and feature films of the 1960s. These productions were created by Gerry and Sylvia Anderson and filmed at APF's studios on the Slough Trading Estate. The characters were played by electronic marionettes with a moveable lower lip, which opened and closed in time with pre-recorded dialogue by means of a solenoid in the puppet's head or chest. The productions were mostly science fiction with the puppetry supervised by Christine Glanville, art direction by either Bob Bell or Keith Wilson, and music composed by Barry Gray. They also made extensive use of scale model special effects, directed by Derek Meddings.