Cucumber Castle is the seventh studio album by the Bee Gees, released in April 1970. It was produced by Barry Gibb, Maurice Gibb, and Robert Stigwood. It consists of songs from their television special of the same name, which was named after a song on their 1967 album Bee Gees' 1st. Cucumber Castle is the only Bee Gees album not to feature any recorded contributions from Robin Gibb, as he had left the group before the album was recorded. (He did receive co-composer credit on one track, which was written before his departure.)

Cucumber Castle was the last Bee Gees album with drummer Colin Petersen, who was fired during the recording of the album. Pentangle drummer Terry Cox played on the remaining tracks.

This album contained the hit single "Don't Forget to Remember" which hit No. 2 in the UK in August 1969, going virtually head to head with Robin Gibb's solo single "Saved by the Bell", which had reached number No. 2 the previous month. The album struggled to make an impact and stalled at number 57 in the UK and number 94 in the US. Indeed, it was the last Bee Gees album to chart in the UK until Spirits Having Flown in 1979 (though the soundtrack for Saturday Night Fever, which featured six contributions from the group as well as two additional songs that they wrote that other artists performed, topped the UK album chart in 1978).