Christie began playing at age 14, and attended the Guildhall School of Music and Drama. He formed a band with his brother in the late 1940s, and soon after the pair joined the band of Humphrey Lyttelton, recording copiously. Keith served in the military early in the 1950s, then reconvened to lead an ensemble with his brother, the Christie Brothers' Stompers, featuring Ken Colyer and Dicky Hawdon, in 1951. In 1953 they broke up this group, and Keith went on to work with John Dankworth, Cleo Laine, George Chisholm, Harry Klein, Kenny Baker, Vic Ash, Wally Fawkes, and Tommy Whittle in the middle of the 1950s.
Christie was a core member of the famous trombone section of the Ted Heath Orchestra from 1957 till the late-1960s, playing alongside Don Lusher. He also played with drummer Allan Ganley, saxophonists Ronnie Ross and Art Ellefson from 1959-–1962 in the Jazzmakers. He also toured the U.S. with Vic Lewis in 1960. After a brief reunion with Heath he played with Jimmy Deuchar (1964) and Harry South (1965–66). In 1970–71 he joined Benny Goodman on a tour of Europe. The 1960s and 1970s also saw him playing with Tubby Hayes, Paul Gonsalves, Ian Hamer, Stan Tracey, Kenny Wheeler, Bobby Lamb and Ray Premru, Phil Seamen, and Tony Kinsey. In the mid-1970s he suffered a fall and recovered, but continuing battles with alcoholism eventually resulted in his early death.
- Henley/Kernfeld, "Keith Christie". Grove Jazz online.