"Calling Occupants of Interplanetary Craft" is a song by Canadian rock band Klaatu, originally released in 1976 on their first album 3:47 EST.

The year following its release, American soft rock duo the Carpenters covered the song, using a crew of 160 musicians.

[6] Woloschuk said: The idea for this track was suggested by an actual event that is described in The Flying Saucer Reader, a book by Jay David published in 1967.

In March 1953 an organization known as the "International Flying Saucer Bureau" sent a bulletin to all its members urging them to participate in an experiment termed "World Contact Day" whereby, at a predetermined date and time, they would attempt to collectively send out a telepathic message to visitors from outer space.

The success of their version led to the duo receiving many letters from people asking when World Contact Day would be held.