"When the Swallows Fly" is a song by the Bee Gees released on their fifth album Idea.

[1] Its promotional video was filmed in Brussels and included on the TV special Idea and was aired on 11 December 1968.

The song's opening line echoed William Wordsworth's poem"I Wandered Lonely as a Cloud".

Barry recalls: "['When the Swallows Fly'] that's something I brought in, but I don't remember how the song came about.

[3] In 1971, when it was included on the Melody film soundtrack, it was released as a single only in Netherlands with "Give Your Best" as the B-side.