Sonelius Smith (born December 17, 1942) is known both for his innovative contributions to jazz as composer and pianist and for his collaborations with some of the late twentieth century's greatest jazz musicians.

As a composer, Smith has created work performed by pianists Ahmad Jamal and Stanley Cowell and saxophonists David Murray and Robin Kenyatta. As a jazz pianist, Smith has performed with Charles Mingus, Lionel Hampton and Stanley Cowell, and been a member of several noteworthy musical groups, including the Piano Choir, which the Washington Post described in 2000 as a multi-genre "Masters of the Piano ... [s]et up on nine Steinway pianos in a semicircle with the keys facing the audience [showcasing] the best of three centuries of piano history." In 1977, the New York Times described Smith's performance with Clifford Thornton's jazz quintet as "forcefully inventive." In 1991, AllMusic described the David Murray Big Band album, which Smith recorded as a member of the David Murray Quartet, as "generally brilliant."

Between 1970 and 2001, Smith performed, played or composed the music for some forty-five albums, including one of his own: The World of the Children (1977), originally released by the storied Strata-East Records, but remastered by Pure Pleasure Records Ltd. in 2021. In a review of the remastered edition, Robbie Gerson of the UK's Audiophile Audition praised its "aspirational soul, free jazz and lyrical expression" and "Smith (the composer) [for] shin[ing] on acoustic piano with a complicated, transcendental improvisation ... incorporat[ing] both Latin and African patterns," which he described as "captivating," noting that "[a]nother Smith composition (“Conversation Piece”) captures the opposing earthy and graceful abstraction."

In 2005, Smith's collaboration with Shamek Farrah on "Julius" was included in Mastercuts Breaks, a compilation released by Mastercuts that also featured Earth, Wind & Fire, James Brown and Nina Simone.