Jefferson County Map
The County of Jefferson is located in the State of Missouri. Find directions to Jefferson County, browse local businesses, landmarks, get current traffic estimates, road conditions, and more. According to the 2020 US Census the Jefferson County population is estimated at 226,543 people. The Jefferson County time zone is Central Daylight Time which is 6 hours behind Coordinated Universal Time (UTC).
Nearby counties include Monroe County, Franklin County, Ste. Genevieve County, St. Francois County, St. Louis County, Washington County.
Top cities include Arnold, Festus, House Springs, Kimmswick, Byrnes Mill