Gilmour was born in Cambridge, England. His father, Douglas Gilmour, was a senior lecturer in zoology at the University of Cambridge and his mother, Sylvia, was a teacher and film editor.
Gilmour attended The Perse School on Hills Road, Cambridge, and met future Pink Floyd guitarist and vocalist Syd Barrett who attended Cambridgeshire High School for Boys, also situated on Hills Road. He studied modern languages to A-Level, and along with Syd, spent his lunchtime learning to play the guitar. They were not yet bandmates however, and Gilmour started playing in the band Joker’s Wild in 1963.
Gilmour left Joker’s Wild in 1966 and busked around Spain and France with some friends. However, they were not very successful, living virtually a hand-to-mouth existence. In July 1992, Gilmour stated in an interview with Nicky Horne on BBC radio that he ended up being treated for malnutrition in a hospital. In 1967, they returned to England, driving a van with fuel stolen from a building site in France.