`` When I 'm Sixty-Four '' is a love song by The Beatles , written by Paul McCartney ( credited to Lennon\/McCartney ) and released in 1967 on their album Sgt. Pepper 's Lonely Hearts Club Band . `` When I 'm Sixty-Four '' is a song by The Beatles , written by Paul McCartney ( credited to Lennon\/McCartney ) and released in 1967 on their album Sgt. Pepper 's Lonely Hearts Club Band .