Koz was born March 27, 1963, in Encino, California, and played in his high school jazz band before graduating from UCLA in 1986 with a degree in mass communications. Within weeks of deciding to pursue music professionally, he was recruited for Bobby Caldwell's touring band. He spent the rest of the 1980s as a session musician, touring with Jeff Lorber and later joining Richard Marx's band for several years.

His self-titled solo debut arrived in 1990 and climbed onto the Billboard contemporary jazz charts, launching a recording career that would eventually produce nine Grammy nominations, five No. 1s on the contemporary jazz charts, 14 Top Ten singles, and 20 total cuts on the jazz songs charts. In 1994 he began hosting the syndicated Dave Koz Radio Show, featuring music and interviews across the smooth jazz world, and later co-hosted The Dave Koz Morning Show on Los Angeles smooth jazz station 94.7 The Wave for six years.

Koz's melodic, radio-friendly saxophone style places him alongside Kenny G and Kirk Whalum as one of smooth jazz's defining commercial voices, and his parallel career as a radio host gave him a rare dual influence over both the genre's recorded output and how it reached listeners.