The Petaluma Police Court was a municipal-level court that handled minor offenses, as well as initial handling of serious offenses that were subsequently referred to the Superior Court. The Petaluma Police Court was reorganized in 1952 as part of the State of California's inferior court reorganization program authorized by the voters as California Proposition 3 in 1950, which combined the offices of the township justices of the peace and city police court judges; the Petaluma Police Court and other, local municipal courts were combined as the Petaluma Judicial District Court or more formally, the State of California's Municipal Court for the Petaluma Judicial District) on Jan. 1, 1952.

A number of other reorganizations and consolidations of the County's District Courts took place over the next four decades until the District Courts and other inferior courts were absorbed into the Superior Court following another voter-authorized reorganization in 1998, California Proposition 220.