The Restaurant at the End of the Universe is the second book in the Hitchhiker's Guide to the Galaxy comedy science fiction "trilogy" by Douglas Adams, and is a sequel. It was originally published by Pan Books as a paperback in 1980. The book was inspired by the song "Grand Hotel" by British rock band Procol Harum. The book title refers to Milliways, the Restaurant at the End of the Universe, one of the settings of the book. Elements of it are adapted from the radio series, primarily the Secondary Phase, although Milliways itself, Arthur and Ford's final fate come from Fits the Fifth and Sixth of the Primary Phase.

The Hitchhiker's Guide to the Galaxy is the first book in the Hitchhiker's Guide to the Galaxy comedy science fiction "trilogy of five books" by Douglas Adams, with a sixth book written by Eoin Colfer. The novel is an adaptation of the first four parts of Adams's radio series of the same name, centering on the adventures of the only man to survive the destruction of Earth; while roaming outer space, he comes to learn the truth behind Earth's existence. The novel was first published in London on 12 October 1979. It sold 250,000 copies in the first three months.