John Brumwell Mayall OBE (29 November 1933 – 22 July 2024) was an English blues and rock musician, songwriter and producer. In the 1960s, he formed John Mayall & the Bluesbreakers, a band that has counted among its members some of the most famous blues and blues rock musicians of all-time. A singer, guitarist, harmonica player, and keyboardist, he had a career that spanned nearly seven decades, remaining an active musician until his death aged 90. Mayall has often been referred to as the "godfather of the British blues", and was inducted into the Rock and Roll Hall of Fame in the musical influence category in 2024.

Born in Macclesfield, Cheshire, on 29 November 1933, John Brumwell Mayall grew up in Cheadle Hulme. He was the son of Murray Mayall, a guitarist who played in local pubs.

From an early age he was drawn to the sounds of American blues players such as Lead Belly, Albert Ammons, Pinetop Smith, and Eddie Lang, and taught himself to play the piano, guitar, and harmonica.

Mayall was sent to Korea as part of his national service, and during a period of leave bought his first electric guitar in Japan. Back in England, he enrolled at Manchester College of Art and started playing with a semi-professional band, the Powerhouse Four. After graduation, he obtained a job as an art designer, but continued to play with local musicians. In 1963, he opted for a full-time musical career and moved to London. His previous craft would be put to good use in the designing of covers for many of his coming albums.

In 1956, with college fellow Peter Ward, Mayall founded the Powerhouse Four, which consisted of the two men and other local musicians with whom they played at local dances. In 1962 Mayall became a member of the Blues Syndicate. The band was formed by trumpeter John Rowlands and alto saxophonist Jack Massarik, who had seen the Alexis Korner band at a Manchester club and wanted to try a similar blend of jazz and blues. It also included rhythm guitarist Ray Cummings and drummer Hughie Flint, whom Mayall already knew. In 1962 John and his band were frequent and popular artists at all-night R&B sessions at the Twisted Wheel cellar club in central Manchester. Alexis Korner persuaded Mayall to opt for a full-time musical career and move to London, where Korner introduced him to many other musicians and helped them to find gigs.

In late 1963, with his band, which was now called the Bluesbreakers, Mayall started playing at the Marquee Club. The line-up was Mayall, Ward, John McVie on bass and guitarist Bernie Watson, formerly of Cyril Davies and the R&B All-Stars. The next spring Mayall obtained his first recording date with producer Ian Samwell. The band, with Martin Hart at the drums, recorded two tracks: "Crawling Up a Hill" and "Mr. James". Shortly after, Hughie Flint replaced Hart and Roger Dean took the guitar from Bernie Watson. This line-up backed John Lee Hooker on his British tour in 1964.

Mayall was offered a recording contract by Decca records and, on 7 December 1964, a live performance of the band was recorded at the Klooks Kleek. A later studio-recorded single, "Crocodile Walk", was released along with the album, but both failed to achieve any success and the contract was terminated.

In April 1965, former Yardbirds guitarist Eric Clapton replaced Roger Dean and John Mayall's career entered a decisive phase.