Bloomfield was born into a wealthy Chicago family . He began playing in local bands, and Bloomfield put together a group called the Hurricanes, named after Ohio rock band Johnny and the Hurricanes. New Trier High School expelled Bloomfield after his band performed a raucous rock and roll song at a 1959 school gathering.
Bloomfield had attended a 1957 Chicago performance by blues singer Josh White, and began spending time in Chicago's South Side blues clubs and playing guitar with such black bluesmen as Sleepy John Estes, Yank Rachell, and Little Brother Montgomery. He first sat in with a black blues band in 1959, when he performed with Luther "Guitar Junior" Johnson at a Chicago club called the Place. He performed with Howlin' Wolf, Muddy Waters, and many other Chicago blues performers during the early 1960s.
Songwriter and record producer Al Kooper said Bloomfield's talent "was instantly obvious to his mentors. They knew this was not just another white boy; this was someone who truly understood what the blues were all about." Among his early supporters were B.B. King, Muddy Waters, Bob Dylan and Buddy Guy.
"Michael used to say, 'It's a natural. Black people suffer externally in this country. Jewish people suffer internally. The suffering's the mutual fulcrum for the blues.'"
In early 1965 he joined the Paul Butterfield Blues Band, which included Elvin Bishop and keyboardist Mark Naftalin, along with drummer Sam Lay and bassist Jerome Arnold, who had previously worked in Howlin' Wolf's band. Elektra Records producer Paul Rothchild recorded the band in spring 1965, but the majority of the tracks were not released until the 1990s. However, one of the tracks Rothchild recorded during his first pass at producing the group, a Nick Gravenites song titled "Born in Chicago," was included on the Elektra album Folksong '65, which sold two hundred thousand copies when it was released in September 1965. "Born in Chicago" became an underground hit for the Butterfield Band. Their debut album, The Paul Butterfield Blues Band, was recorded in September and released the following month.
In June 1965, Bloomfield had recorded with Bob Dylan, whom he had met in 1963 at a Chicago club called the Bear. The club was bankrolled by future Dylan and Butterfield manager Albert Grossman, who would play a major part in Bloomfield's career. Bloomfield's Telecaster guitar licks were featured on Dylan's "Like a Rolling Stone". Bloomfield would play on most of the tracks on Dylan's 1965 Highway 61 Revisited album, and he appeared onstage with Dylan in July at the Newport Folk Festival, where Dylan used Bloomfield and the Butterfield Band—minus Paul Butterfield—along with keyboardists Al Kooper and Barry Goldberg.
The show marked Dylan's first use of an electric band in a live performance, and Bloomfield's playing on the songwriter's "Maggie's Farm" is considered a landmark electric-guitar performance. After the Newport Folk Festival ended, Bloomfield helped Dylan complete the sessions for Highway 61 Revisited, and Dylan asked Bloomfield to join his touring band. Bloomfield demurred, preferring to continue playing with the Butterfield Band. When Mike Bloomfield departed he form the Electric Flag, an blues rock soul group, with keyboardist Barry Goldberg and drummer Buddy Miles, and featuring other musicians such as vocalist Nick Gravenites and bassist Harvey Brooks.
Rare Mike Bloomfield Live video footage