He was born in Huntington, Long Island to a family of mixed Jewish and Irish-Catholic ancestry. His mother’s family originally came from Vienna, Austria, where his great-grandfather Alfred Roth had been a colonel in the Austro-Hungarian cavalry, the highest rank accessible to a Jew in the Habsburg Imperial army.
After hearing Pee Wee Russell the first time, he was convinced that he wanted to be a jazz musician, too; and at the age of 16 he joined the musician's union, first as a baritone saxophone player. In 1954 he joined Jack Teagarden's Band, and after only a few days with the band he made his first jazz recordings. Later on, he worked with bands led by Phil Napoleon and Pee Wee Erwin before joining the Dukes of Dixieland in 1962. The late 1960s found him free-lancing with, among others, Red Allen, Ralph Sutton, Yank Lawson and his life-long friend Dick Wellstood.
At this time, he had also taken up the soprano saxophone, and when a spontaneous coupling with fellow reedman Bob Wilber at Dick Gibson's Colorado Jazz Party turned out be a huge success, one of the most important jazz groups of the 1970s, Soprano Summit, was born. Co-led by Wilber and Davern, both switching between the clarinet and various saxophones, during the next five years Soprano Summit enjoyed a very successful string of record dates and concerts. When the group disbanded in 1979, Davern devoted himself to solely playing clarinet, preferring trio formats with piano and drums. His collaboration with Bob Wilber was revived in 1991, the new group being called Summit Reunion. Leading his own quartets since the 1990s, Davern has preferred the guitar to the piano in his rhythm section, employing guitarists Bucky Pizzarelli, Howard Alden and James Chirillo.
In 1997, he was inducted into the Jazz Hall of Fame at Rutgers University, and in 2001 he received an honorary doctorate of music at Hamilton College, Clinton, New York. In addition to the jazz greats that inspired him, Kenny Davern indicates classical clarinetist David Weber, principal solo clarinetist with the New York City Ballet Orchestra, as his most important teacher.
Although playing mainly in traditional jazz and swing settings, his musical interests encompass a much broader range of styles. In 1978 he collaborated with avantgarde players Steve Lacy, Steve Swallow and Paul Motian on a free jazz-inspired album appropriately entitled Unexpected. In addition to his accomplishments in jazz, his ardour and knowledge of classical music is encyclopaedic, particularly of the work of conductor Wilhelm Furtwängler.
Especially since he has been concentrating on exclusively playing the clarinet, Kenny Davern has been calling his own an unmatched mastery of the instrument. A full, rounded tone, especially "woody" in the lower chalumeau register, combined with highly personal tone inflections and the ability to hit notes far above the conventional range of the clarinet, have made his sound immediately recognizable. In the late 1980s, the New York Times hailed him as "the finest jazz clarinetist playing today". Kenny died of a heart attack at his Sandia Park, New Mexico home.