[1] Williams is known for his membership in pianist Herbie Hancock's early 1970s group, as well as working with guitarist Larry Coryell, the Thelonious Monk repertory band Sphere and as the accompanist of choice for many singers, including Nancy Wilson.

Williams was particularly inspired to focus on bass after hearing his father's record of Star Dust, performed by Oscar Pettiford, and started playing in his early teens.

[2] Just after graduating high school in 1960, Williams had the opportunity to play with Gene Ammons and Sonny Stitt when Nelson Boyd reached out to Charles Sr. to cover for him.

After the first set on a Friday night, Ammons and Stitt asked Williams to join the band on tour, starting in Chicago, after playing through the weekend in Philadelphia.

[3][4][5] Williams would go on to work with numerous other vocalists throughout his career, including Sathima Bea Benjamin, Shirley Horn, Betty Carter, Jonathan Schwartz, Carmen McRae, Roseanna Vitro, Helen Merrill, Nnenna Freelon, Jon Lucien, Marguerite Mariama, and Champian Fulton.

According to Williams, he was "the number one sub for Ray Brown" during this time, playing with Kenny Dorham, recording a date with the Harold Land/Bobby Hutcherson quintet, and ultimately working with Miles Davis for several months in 1967.

[3][4][5][6] In October 1968, Williams moved to New York City and continued to work steadily, playing shows with Art Blakey, Herbie Mann, and Mary Lou Williams, while recording for Atlantic, Blue Note, and Prestige with artists such as McCoy Tyner, Dexter Gordon, Roy Ayers, Stanley Turrentine, Frank Foster, Illinois Jacquet, and, once again, Gene Ammons (recently returned from a seven-year stint in Joliet).

1982 saw Williams form two important collaborative ensembles, the Timeless All-Stars, a sextet featuring Harold Land, Curtis Fuller, Bobby Hutcherson, Cedar Walton, and Billy Higgins, which recorded four albums for the Dutch label Timeless Records, and Sphere, featuring Kenny Barron, Ben Riley, Charlie Rouse, and later Gary Bartz.

Williams reunited with Ron Carter for Alain Corneau's 1981 film Le Choix des Armes, with music composed by Philippe Sarde and performed by the London Symphony Orchestra.

In the 1990s, Williams worked with Angelo Badalamenti on David Lynch's Twin Peaks: Fire Walk with Me and with Terence Blanchard for the Spike Lee film Clockers.

"[21] Williams' instrument is a copy of a late-1800s Boosey & Hawkes Panormo, using La Bella strings and a Fishman BP-100 pickup, with a 1x15 Polytone Mini-Brute bass amp.

[6] With Geri Allen With Gene Ammons With Roy Ayers With Angelo Badalamenti With Chet Baker With Kenny Barron With Sathima Bea Benjamin With Art Blakey With Ron Carter With Cyrus Chestnut With Norman Connors With Larry Coryell With Sonny Fortune With Benny Golson With Dexter Gordon With Herbie Hancock With Billy Hart With Eddie Henderson With Buck Hill With Shirley Horn With Bobby Hutcherson With Abdullah Ibrahim With The Jazz Crusaders With Steve Kuhn With Harold Land With Harold Mabern With John McNeil With Meeco With Frank Morgan With David "Fathead" Newman With Houston Person With Wallace Roney With Jimmy Rowles With Hilton Ruiz With Woody Shaw With Sphere With Buddy Terry With The Timeless All Stars With Steve Turre With Stanley Turrentine With McCoy Tyner With Michal Urbaniak With Cedar Walton With Mary Lou Williams With Nancy Wilson With Denny Zeitlin With Others