Codes & Ordinances

The Unified Development Order (UDO) was adopted on April 2, 2008 and has been amended from time to time. The UDO is contained in Chapter 400 of the Code of Ordinances of Jefferson County.

The Official Master Plan (PDF) for Jefferson County was adopted on August 6, 2003.

Proposed Code Amendments:

Notice is hereby given that the Planning and Zoning Commission of Jefferson County, Missouri, will conduct a public hearing at 6:30 p.m., Thursday, February 9, 2023, in the Jefferson County Administration Center, Assembly Room, 729 Maple Street, Hillsboro, Missouri.  The purpose of the hearing is to receive comments, both written and oral, prior to adoption of amendments to the Code of Ordinances of Jefferson County, Missouri, Chapter 400: Unified Development Order.

Representatives of the media may obtain copies of this notice by contacting the Jefferson County Planning Division, PO Box 100, Hillsboro, Missouri 63050, 636-797-5580.  Interested parties may examine a copy of the amendments to the UDO at the following locations: Jefferson County Planning Division Office, 725 Maple Street, Hillsboro and online at

Any person requiring special accommodation under the Americans with Disabilities Act should contact Jefferson County Human Resources, at 636-797-5071.