Ronnie Scott was born Ronald Schatt on January 28, 1927, in Aldgate in London's East End, into a Jewish family; his father, Joseph Schatt, was of Russian descent. He went to the Central Foundation Boys' School and was playing in small jazz clubs by sixteen, having tried a cornet and a soprano saxophone before settling on the tenor. He toured with the trumpeter Johnny Claes in 1944 and 1945 and joined Ted Heath's band in 1946, the year he also appeared as a band member in the film George in Civvy Street. Like many British players of his generation he worked on the Cunard liner Queen Mary between 1946 and about 1950, a job that let him hear bebop in New York clubs, and he became one of the first British musicians shaped by Charlie Parker. He also got to know the arranger Tadd Dameron, who was then working in Britain for Heath.

From late 1948 to 1950 he was part of Club Eleven, a musicians' cooperative band and club in London run with the alto saxophonist Johnny Dankworth that is usually described as Britain's first club devoted to modern jazz. His earliest records, among them "Boppin' at Esquire" and "Idabop" (recorded January 13, 1948, and issued that May under the name the Esquire Five), were made for the small Esquire label, which went on to issue his Boptet sides of 1949 to 1952 and his quintet and orchestra records of the mid-1950s. After a spell in Jack Parnell's orchestra in 1952 he began leading his own bands in 1953: a nine-piece group and a quintet that, through 1956, included the tenor saxophonist Pete King, the pianist and drummer Victor Feldman, the trumpeter Hank Shaw and the drummer Phil Seamen. A short-lived big band followed in 1955. On February 18, 1956, his orchestra with the drummer Tony Crombie played the National Jazz Federation's "Jazz Scene 1956" concert at the Royal Festival Hall, and in January 1957 his sextet recorded Presenting the Ronnie Scott Sextet for Philips.

In 1957 he and the tenor saxophonist Tubby Hayes formed the Jazz Couriers, a two-tenor quintet that opened at the new Flamingo Club in Wardour Street, Soho, on April 7, 1957. The National Jazz Federation chose the group to play the opening sets when the Dave Brubeck Quartet made its first British tour in February 1958. The Couriers made four albums for Tempo and Carlton, including the live In Concert, recorded at the Dominion Theatre on February 16, 1958, and broke up in August 1959. Scott and King, the group's manager, then borrowed the money to open Ronnie Scott's Jazz Club in a basement at 39 Gerrard Street on October 30, 1959. Business picked up when the club began booking American tenor players: Zoot Sims played a residency in November 1961, and Johnny Griffin, Lee Konitz, Sonny Rollins, Sonny Stitt, Dexter Gordon, Rahsaan Roland Kirk, Stan Getz and Ben Webster followed in the years after. In 1965 the club moved to 47 Frith Street, while the old room carried on as the Old Place, a venue for younger British players, until its lease ran out in 1967. Scott acted as master of ceremonies and was noted for his jokes and one-liners; Jimi Hendrix gave his last public performance there in 1970.

He kept playing through all of it. His quartet with the pianist Stan Tracey ran from 1960 to 1967, and live sets from the club's first room, taped in 1963 to 1965, were released long afterwards, among them a May 1964 night with Sonny Stitt issued in 1997 as The Night Has a Thousand Eyes. From 1967 to 1969 he sat in the saxophone section of the Kenny Clarke and Francy Boland big band, which toured Europe, and he is credited on that band's records from Handle with Care (recorded in Cologne in January 1963) onward. Alongside it he led his own bands, among them one with John Surman and Kenny Wheeler that recorded Live at Ronnie Scott's at the club on October 25 and 26, 1968, billed as Ronnie Scott and the Band. A trio with the keyboard player Mike Carr and the drummer Bobby Gien worked from 1971 to 1975, and his later quintets often featured the pianist John Critchinson and the drummer Martin Drew. His session credits include the tenor solo on the Beatles' "Lady Madonna" (overdubbed on February 6, 1968), a solo on Roy Budd's score for the film Fear Is the Key (1972), and the tenor part on Phil Collins's "I Missed Again" (1981). He was made an Officer of the Order of the British Empire in the 1981 New Year Honours. The club's own label, Ronnie Scott's Jazz House, founded in 1978, issued his later quintet records, but he recorded only occasionally in his last decades.

Scott suffered from depression. He passed away in London on December 23, 1996, at 69, from an accidental overdose of barbiturates prescribed by his dentist while he was recovering from tooth-implant surgery; the Westminster coroner's inquest in February 1997 recorded a verdict of death by misadventure. Pete King ran the club for nine more years and sold it in June 2005 to the theatre impresario Sally Greene, with the philanthropist Michael Watt. As of November 2026 it still operates at 47 Frith Street. His widow, Mary Scott, and her daughter Rebecca wrote a memoir, A Fine Kind of Madness: Ronnie Scott Remembered (1999), and he told his own story with Mike Hennessey in Some of My Best Friends Are Blues.

Scott was a bebop-rooted tenor saxophonist whose sound, in the words of AllMusic's biographer, was lyrical but harmonically complex, and he belonged to the first British generation that took its cue from Charlie Parker rather than from the swing bands. He co-led the two-tenor Jazz Couriers with Tubby Hayes and worked through the 1960s in a quartet with the pianist Stan Tracey. Charles Mingus said in 1961 that Scott, like Zoot Sims, came closer to the blues feeling than most white players, and Sims was the first American guest the club booked. His late-1960s band, with John Surman and Kenny Wheeler in it, drew in younger British players, and from the 1970s he led trios and quintets built around his regular rhythm sections. His influence on British jazz rests as much on the room he built as on his records: for more than six decades the Soho club has been where visiting American players and young British musicians shared a bandstand.