He studied oboe and composition at Jacksonville University from 1965 to 1967, then finished his education at Georgia State College in 1969. He also taught piano and jazz improvisation at Jacksonville University for several years.
He, along with alligator wrestler Chris Lightburn and Rev. H. L. Patterson of St. Mary's Baptist Church, founded the Lincolnville Restoration and Development Commission in his home town of St. Augustine in 1978. One of the group's projects was the organizing, in 1979, of the annual Lincolnville Festival, which has continued into the 21st century and become one of the Ancient City's leading cultural events.
Carn recorded several albums on the Black Jazz Records label during the 1970s that have since achieved cult classic status, including Infant Eyes, Adam's Apple, and Revelation. He worked with Nat Adderley, Earth, Wind & Fire, Shirley Horn, Lou Donaldson, Stanley Turrentine, and Irene Reid. Most recently, he was featured on drummer Cindy Blackman's (of Lenny Kravitz fame) latest release, Another Lifetime.
- 1969: The Doug Carn Trio (Savoy Records)
- 1971: Infant Eyes (Black Jazz)
- 1972: Spirit of the New Land (Black Jazz)
- 1973: Revelation (Black Jazz)
- 1975: Adam's Apple (Black Jazz)
- 1977: Al Rahman! Cry Of The Floridian Tropic Son
- 1996: The Best of Doug Carn (Universal Sound)
- 2001: New Incentive: Firm Roots (Black Jazz)
With Melvin Van Peebles
- As Serious as a Heart-Attack (1974)
With Cindy Blackman
- Another Lifetime (2010)