Brian Johncock (born 29 June 1939) is a British designer and director of film and television special effects. He changed his surname to Johnson during the 1960s.

Joining the team of special effects artist Les Bowie, Johnson started his career behind the scenes for Bowie Films on productions such as On the Buses, and for Hammer Films. He is known for his special effects work on TV series including Thunderbirds (1965–66) and films including Alien (1979), for which he received the 1980 Academy Award for Best Visual Effects (shared with H. R. Giger, Carlo Rambaldi, Dennis Ayling and Nick Allder). Previously, he had built miniature spacecraft models for Stanley Kubrick's 1968 film 2001: A Space Odyssey.

Johnson's work on Space: 1999 influenced the effects of the Star Wars films of the 1970s and 1980s. Impressed by his work, George Lucas visited Johnson during the production of the TV series to offer him the role of effects supervisor for the 1977 film. Having already been commissioned for the second series of Space: 1999, Johnson was unable to accept at the time. He worked on the sequel, The Empire Strikes Back (1980), whose special effects were recognised in the form of a 1981 Special Achievement Academy Award (which Johnson shared with Richard Edlund, Dennis Muren and Bruce Nicholson).