Marvin the Paranoid Android is a fictional character in The Hitchhiker's Guide to the Galaxy series by Douglas Adams. Marvin is the ship's robot aboard the starship Heart of Gold. Originally built as one of many failed prototypes of Sirius Cybernetics Corporation's GPP technology, Marvin is afflicted with severe depression and boredom, in part because he has a "brain the size of a planet" which he is seldom, if ever, given the chance to use. Instead, the crew request him merely to carry out mundane jobs such as "opening the door". Indeed, the true horror of Marvin's existence is that no task he could be given would occupy even the tiniest fraction of his vast intellect. Marvin claims he is 50,000 times more intelligent than a human, though this is, if anything, an underestimation. When kidnapped by the bellicose Krikkit robots and tied to the interfaces of their intelligent war computer, Marvin simultaneously manages to plan the entire planet's military strategy, solve "all of the major mathematical, physical, chemical, biological, sociological, philosophical, etymological, meteorological and psychological problems of the Universe, except his own, three times over", and compose several lullabies.

The Hitchhiker's Guide to the Galaxy is a comedy science fiction franchise created by Douglas Adams. Originally a 1978 radio comedy broadcast on BBC Radio 4, it was later adapted to other formats, including novels, stage shows, comic books, a 1981 TV series, a 1984 text adventure game, and 2005 feature film.