While he initially studied piano, Swarbrick was directed to the fiddle by pianist Beryl Marriott in the 1950s. Sharpening his musical skills with the Ian Campbell Folk Group, in a duo with British guitarist Martin Carthy, and as accompanist for British folklorist A.L. Lloyd, Swarbrick released his debut solo album, Rags, Reels & Airs, in 1967. A guest fiddler on Fairport Convention's album, Unhalfbricking in 1969, Swarbrick was a full-fledged member when they recorded their next album, Liege & Lief the following year. He continued to be an essential member of the band for nearly a decade. In addition to playing electric fiddle with the band, Swarbrick contributed several original songs and sang lead on such tunes as "Rosie." The group's electric approach, however, resulting in severe hearing loss. Since leaving Fairport in 1979, Swarbrick has concentrated on acoustic music. In the early '80s, Swarbrick toured with Fairport Convention guitarist and vocalist Simon Nicol, recording two albums -- Close to the White Bear in 1981 and Close to the Wind in 1984.

Swarbrick celebrated his 50th birthday with a concert on April 6, 1991, at Birmingham Town Hall that featured many of the musicians from his past. In addition to a set by Beryl Marriott's Ceili Band, the evening featured performances by the Ian Campbell Folk Group, Martin Carthy, and Fairport Convention. Highlights from the evening were released as Folk on 2 in 1996. Swarbrick was also featured on two duo albums that year: Saturday Johnny and Johnny the Rat was recorded with Alistair Hulett, a Glasgow-born guitarist who spent 17 years in Australia, while Secrets, Vows and Lies was recorded with Australian guitarist Pete Hawes.