John Denver wrote "Leaving on a Jet Plane" during a layover at a Washington airport in 1967. Denver recorded the first version of the song with his band at the time, the Chad Mitchell Trio.
"Leaving on a Jet Plane" became popular when the group Peter, Paul and Mary recorded it in 1969, helping to launch Denver's career. The song was both the biggest and last hit for Peter, Paul and Mary, and the first for John Denver.
Originally named "Babe I Hate to Go," the song was renamed to "Leaving on a Jet Plane" at the encouragement of Milt Okun, Denver's producer at the time.