Arthur Philip Dent was a human being from the planet Earth. After his planet was destroyed by the Vogons, he was saved by Ford Prefect, who was to become his traveling companion as Arthur traversed the galaxy, his misadventures being the basis for The Hitchhiker's Guide To The Galaxy story.
The Hitchhiker's story begins with Earth being destroyed by the Vogons in an effort to create a hyperspace bypass. Arthur is rescued by a friend, Ford Prefect, and through a highly improbable coincidence, ends up on the starship Heart of Gold, where they meet Trillian, a fellow human being, and Zaphod Beeblebrox, an alien and former associate of Ford. Ford, Zaphod, and Trillian embark on a perilous quest to find the lost planet of Magrathea, with the bewildered Arthur tagging along. He was killed on Earth when the Vogons destroyed it again, as well as any chance of it ever existing in any universe again.
Arthur Dent was portrayed by Simon Jones in the LP, radio, and television versions of the story, by Chris Langham in the 1979 stage version, and by Martin Freeman in the 2005 film.