Born in Chicago and growing up in Boston, Williams began studies with master drummer Alan Dawson at an early age and began playing professionally at the age of 13 with saxophonist Sam Rivers. Jackie McLean hired Williams at 16. At 17 Williams found considerable fame with Miles Davis, joining a group that was later dubbed Davis's "Second Great Quintet." His first album as a leader, 1964's Life Time (not to be confused with the name of his band "Lifetime," which he formed several years later) was recorded during his tenure with Davis.
Williams was a vital element of the group, called by Davis in his autobiography "the center of the group's sound".  His inventive playing helped redefine the role of jazz rhythm section through the use of polyrhythms and metric modulation (transitioning between mathematically related tempos and/or time signatures). But perhaps his overarching achievement was in demonstrating, through his playing, that the drummer need not be relegated to timekeeping and accompaniment in a jazz ensemble; that the drummer may be free to contribute to the performance as an equal partner in the improvisation.
In 1969, he formed a trio, "The Tony Williams Lifetime," with John McLaughlin on guitar and Larry Young on organ. It was a pioneering band of the fusion movement, a combination of rock, R&B, and jazz. Their first album, Emergency!, was largely rejected by the jazz community at the time of its release. However, Miles Davis was so impressed with the album and its highly experimental direction that he asked to head the group as his own; Williams declined. Nowadays, Emergency! is considered by many to be a fusion classic.
After McLaughlin's departure, and several more albums, Lifetime disbanded. In 1975, Williams put together a band he called "The New Tony Williams Lifetime," featuring bassist Tony Newton, pianist Alan Pasqua, and English guitarist Allan Holdsworth, which recorded two albums for Columbia Records, Believe It and Million Dollar Legs respectively.
In mid 1976, Williams was a part of a reunion of sorts with his old Miles Davis band compatriots, pianist/keyboardist Herbie Hancock, bassist Ron Carter and tenor saxophonist Wayne Shorter. Miles backed out of the reunion at the last minute and was replaced by Freddie Hubbard. The record was later released as V.S.O.P. (which stood for a "Very Special OneTime Performance") and was highly instrumental in increasing the popularity of acoustical jazz. The group went on to tour and record for several years, releasing a series of live albums under the name "V.S.O.P." or "The V.S.O.P. Quintet." (The CD reissues of these albums are sold under Herbie Hancock's name - making things a bit confusing since the original V.S.O.P. album, which alone was a Hancock album, has never been released on CD.)