"Leaving on a Jet Plane" is a song written by John Denver in 1966. It expresses the feelings of longing and sadness experienced when departing from a loved one. The lyrics convey a sense of uncertainty about returning, highlighting the emotional struggle of leaving. The song gained popularity when it was covered by the group Peter, Paul and Mary in 1969. Their version became a hit, reaching the top of the charts and solidifying the song's place in popular music. It remains a poignant reminder of love and separation, resonating with listeners across generations.