Barney Kessel was born on October 17, 1923, in Muskogee, Oklahoma, to a Jewish family; his father was a Hungarian immigrant who ran a shoe shop. He taught himself guitar, with only about three months of formal lessons at the age of twelve, and his model was the Oklahoma-raised electric guitar pioneer Charlie Christian, whom he met as a teenager and later called a life-changing influence. He began touring with local swing bands in his early teens, at sixteen joined Hal Price and the Varsitonians, a band from Oklahoma A&M, and was for a time the only white player in all-Black bands working Black clubs.

In the early 1940s he moved to Los Angeles and spent a year in Chico Marx's big band. Norman Granz noticed him there, and in 1944 Kessel was the guitarist in Jammin' the Blues, the short film Granz and the photographer Gjon Mili built around Lester Young; he was the only white musician in the cast, and the film seats him in shadow with his hands stained with berry juice so that the band would not read as mixed. He then played in the bands of Charlie Barnet and Artie Shaw, and was among the soloists of Shaw's 1944 to 1945 band. In February 1947 he joined Charlie Parker in Los Angeles for the session that produced Relaxin' at Camarillo. From 1947 through 1960 he was ranked the top guitarist in the Esquire, DownBeat and Playboy polls, and in the early 1950s he toured with Granz's Jazz at the Philharmonic.

Kessel was the guitarist in Oscar Peterson's trio with Ray Brown in 1952 and 1953, including a 1952 tour of fourteen countries, until Herb Ellis took the chair after Kessel tired of the road. From late 1953 he recorded for Lester Koenig's Contemporary Records in Los Angeles: a ten-inch debut cut in November and December 1953, the standards sets that followed, To Swing or Not to Swing (recorded 1955) and then, from March 1957, a run of trio albums with Brown and the drummer Shelly Manne released under the name The Poll Winners, after the magazine polls all three kept winning. Away from his own dates he was the guitarist, with bassist Ray Leatherwood, on Julie London's 1955 debut Julie Is Her Name, which holds "Cry Me a River", and on Verve he played on Billie Holiday's 1957 albums with Ben Webster, Harry Edison and Jimmy Rowles. In October 1958 he joined Sonny Rollins, Hampton Hawes, Leroy Vinnegar and Manne for the date released as Sonny Rollins and the Contemporary Leaders.

In the 1960s Kessel worked for Columbia Pictures as a first-call guitarist and became one of the Los Angeles studio players later grouped as the Wrecking Crew, playing on sessions for Phil Spector, the Beach Boys, the Monkees and many other pop acts, and on television and film scores. He is credited with the lead electric 12-string part on the Beach Boys' "Wouldn't It Be Nice", played through a Danelectro Bellzouki plugged straight into the recording console at Brian Wilson's request. Kay made a signature series of his guitars in 1957 and 1958, and Gibson built the Barney Kessel model from 1961 to 1974. In the late 1960s he stepped back from studio work and based himself for a time in London, touring Britain and Europe and making albums in London, Rome and Paris, among them I Remember Django with Stéphane Grappelli, recorded in Paris in June 1969 and issued in 1971.

In 1973 he formed the touring trio Great Guitars with Charlie Byrd and Herb Ellis, which played together on and off through the 1980s and recorded a series of live albums, the first in 1975. He made Solo, his only unaccompanied album, in the early 1980s, and in 1986 released an instructional video series, Jazz Guitar Improvisation. A stroke in 1992 ended his playing career. Kessel died of a brain tumor at his home in San Diego on May 6, 2004, at the age of eighty. His sons Dan and David Kessel became record producers and session musicians.

Kessel was known for an unusually deep command of chords and inversions and for chord-melody playing, set against fluent single-note bebop lines with a strong blues undertone. The educator Wolf Marshall called his style the natural outgrowth of the electric tone Christian developed, and he built his sound on hollow-body archtop guitars played with the neck pickup, in a warm, clean timbre; for most of his career his main instrument was a Gibson ES-350P of the late 1940s that he modified with a Charlie Christian bar pickup. He named Charlie Parker, Pat Martino, Oscar Peterson, Lester Young and Django Reinhardt among his influences. On records such as Julie Is Her Name he used the guitar and bass alone to give a singer a full orchestral backdrop, and his trio with Brown and Manne put the guitar at the front of a bass-and-drums trio at a time when piano trios dominated the field. The guitarists who credit him include Steve Howe of Yes, and Pete Townshend recorded the instrumental "To Barney Kessel" for his 1983 album Scoop. The vibraphonist Chuck Redd, who toured with him in the early 1980s, recorded the tribute album Chuck Redd Remembers Barney Kessel in 2006.