He was born Anthony James Donegan in Glasgow in Scotland, the son of a professional violinist. He moved with his mother to London at an early age, after his parents divorced. Inspired by blues music and New Orleans jazz bands he heard on the radio, he resolved to learn the guitar, and bought his first one at the age of 14.
The first band he played in was led by Chris Barber, who approached him on a train asking him if he wanted to audition for his group. Barber had heard that Donegan was a good banjo player—in fact, Donegan had never played the banjo at this point, but he bought one and managed to bluff his way through the audition. His stint in this group was interrupted, however, when he was called up for National Service in 1949.
In 1952, he formed his first group, the Tony Donegan Jazzband, which found some work around London. On one occasion they opened for the blues musician Lonnie Johnson at the Royal Festival Hall. Donegan was a big fan of Johnson, and took his first name as a tribute to him. The story goes that the host at the concert got the musicians' names confused, calling them "Tony Johnson" and "Lonnie Donegan", and Donegan was happy to keep the name.
Donegan was the first person to become famous playing skiffle in the UK. He sang and played both guitar and banjo. His records were somewhat unusual for skiffle, in that they did not feature a tea-chest bass, and only his first record featured a washboard.
That record was a version of Leadbelly's "Rock Island Line", and is probably still his best known. It was the first debut record to go gold in Britain, and reached the top ten in the United States. He later had successes with "Cumberland Gap" and "Does Your Chewing Gum Lose It's [sic] Flavour on the Bedpost Over Night?". "My Old Man's A Dustman" was something of a return to music hall styles, and was not well received by fans, but it reached number one in the UK charts and sold a million copies.
Donegan was unfashionable and generally ignored through the late 1960s and 1970s (although he wrote "I'll Never Fall in Love Again" for Tom Jones in 1969), and he began to play on the American cabaret circuit. He returned to the public's attention in 1978, when he made a record of his early songs with such figures as Ringo Starr, Elton John and Brian May called Putting on the Style. He experienced another late renaissance when in 2000 he released The Skiffle Sessions – Live In Belfast, a critically acclaimed album made with Van Morrison. He also played at the Glastonbury Festival.
Donegan's influence on the generation of musicians that followed him is unquestioned. He inspired both John Lennon and Pete Townsend to learn to play the guitar, and was responsible for hundreds of other skiffle groups being formed. One of them, The Quarrymen, later evolved into The Beatles.
He died in Peterborough, mid-way through a UK tour. He had suffered several heart attacks in the years leading up to his death.