The Castle Jazz Band was a Portland-based Dixieland jazz band, part of the West Coast Revival of traditional jazz music. The Castle Jazz Band started in 1944 and was led by banjoist Monty Ballou. The band released a series of recordings on its own Castle Records label. Cornet player Don Kinch claimed that one of these records, Floating Down the Old Green River, sold more than a million copies. The band disbanded in 1951, and Ballou formed a new version of the band that performed in a club called the Diamond Horseshoe. Ballou sold the club in 1954 and disbanded The Castle Jazz Band in order to join Doc Evans. Ballou periodically reformed the group for concerts and recordings, including sessions in 1968 and 1972.

Ernie Carson, who performed with The Castle Jazz Band in the 50s, later led a group called The Castle Jazz Band, years after the demise of the original group. Please use The Castle Jazz Band for recordings made after 1977.