Thunderbird 6 is a 1968 British science-fiction adventure film written by Gerry and Sylvia Anderson, directed by David Lane and produced by Century 21 Cinema. A sequel to 1966's Thunderbirds Are Go, it was the second film to be adapted from the 1960s television series Thunderbirds, which combined scale models and special effects with marionette puppet characters in a filming process that the Andersons termed "Supermarionation". Intended to provide a lighter-hearted cinematic experience to contrast with the harder science of Thunderbirds Are Go, the Andersons elected to base the plot of Thunderbird 6 on Skyship One, a futuristic airship that is the latest project of the scientist Brains.

Alan, Tin-Tin, Lady Penelope and Parker represent International Rescue on Skyship One's round-the-world maiden flight, unaware that criminal mastermind the Hood is once again plotting to acquire the secrets of the Thunderbird machines. Paid agents of the Hood murder the original crew of Skyship One prior to take-off and assume their identities, entertaining the guests while scheming to lure the Tracy brothers into a trap. Meanwhile, Brains' efforts to produce a satisfactory design concept for Jeff's proposed Thunderbird 6 collide with fate when Skyship One is damaged and Alan's old Tiger Moth biplane appears to be the only hope of saving the International Rescue group and their impostor hosts.