"The Man from MI.5" is an episode of Thunderbirds, a British Supermarionation television series created by Gerry and Sylvia Anderson and filmed by their production company AP Films (APF) for ITC Entertainment. Written by Alan Fennell and directed by David Lane, it was first broadcast on 20 January 1966 on ATV Midlands as the 17th episode of Series One. It is the 20th episode in the official running order.