Alexandra Elene MacLean "Sandy" Denny (6 January 1947 – 21 April 1978) was an English singer and songwriter, perhaps best known as the lead singer for the folk rock band Fairport Convention. She has been described as "the pre-eminent British folk rock singer".
After briefly working with British folk band the Strawbs, Denny joined Fairport Convention in 1968, remaining with that band until the end of 1969. She formed the short-lived band Fotheringay in 1970, releasing one album with them (another unreleased album surfaced over thirty years later), before focusing on a solo career. Between 1971 and 1977, Denny released four solo albums: The North Star Grassman and the Ravens, Sandy, Like an Old Fashioned Waltz, and Rendezvous. She is also noted as the only guest vocalist on a Led Zeppelin studio album, when she shared a duet with Robert Plant for "The Battle of Evermore" on Led Zeppelin's untitled fourth album (1971).
Music publications Sunday Express, Uncut and Mojo have each called Denny Britain's finest female singer-songwriter. Her composition "Who Knows Where the Time Goes?" has been recorded by many artists as diverse as Judy Collins, Nina Simone, 10,000 Maniacs and Cat Power.