David Cyril Eric Swarbrick (5 April 1941 – 3 June 2016) was an English folk musician and singer-songwriter. He has been described by Ashley Hutchings as 'the most influential fiddle player bar none' and his style has been copied or developed by almost every British and many world folk violin players who have followed him. He was one of the most highly regarded musicians produced by the second British folk revival, contributing to some of the most important groups and projects of the 1960s, and he became a much sought-after session musician, which led him throughout his career to work with many of the major figures in folk and folk rock music.

A member of Fairport Convention from 1969, he is credited with leading them to produce their seminal album Liege & Lief (1969) which initiated the British folk rock movement. This, and his subsequent career, helped create greater interest in British traditional music and was highly influential within mainstream rock. After 1970 he emerged as Fairport Convention's leading figure and guided the band through a series of important albums until its disbandment in 1979.

He also played in a series of smaller, acoustic units and engaged in solo projects. He maintained a massive output of recordings and a significant profile and made a major contribution to the interpretation of traditional British music.