A Momentary Lapse of Reason is the thirteenth studio album by the English progressive rock group Pink Floyd, released in the UK and US in September 1987. It followed guitarist David Gilmour's decision to include material recorded for his third solo album on a new Pink Floyd album with Pink Floyd drummer Nick Mason and keyboardist Richard Wright. Although for legal reasons Wright could not be re-admitted to the band, with Mason he helped Gilmour craft what became the first Pink Floyd album since the departure of bass guitarist, singer, and primary songwriter Roger Waters in December 1985.

A Momentary Lapse of Reason was recorded primarily on Gilmour's converted houseboat, Astoria. Its production was marked by an ongoing legal dispute with Waters as to who owned the rights to Pink Floyd's name, an issue resolved several months after the album was released. Unlike many of Pink Floyd's studio albums, A Momentary Lapse of Reason has no central theme and is instead a collection of songs written by Gilmour, sometimes with outside songwriters.

Though it was derided by Waters, A Momentary Lapse of Reason outsold Pink Floyd's previous album The Final Cut (1983) and was supported by a successful world tour. It has been certified quadruple platinum in the United States. More: en.wikipedia.org.