Marion County is located in the northeast corner of Missouri and covers an area of 502 square miles. The county seat is Palmyra.

The county is governed by a three-member County Commission, elected by county residents every four years. Other elected officials in the county include Sheriff, Prosecuting Attorney, Circuit Clerk, Public Administrator, and five members of the County Assessor's Office.

The main industries of the county are agriculture, manufacturing, retail commerce, agriculture services, lumber and wood products, and printing and publishing. Agriculture produces mainly cattle, hogs, corn, soybeans, hay, and soybean seed.

The county is served by two newspapers: the Daily Star-News and the Marion County Democrat. The county also has two school districts and two fire protection districts.

Marion County is part of the Hannibal Micropolitan Statistical Area. The county is home to the Mark Twain Cave and Campground, a historical attraction in Hannibal.

For the most up-to-date and in-depth information, please check the public records links below.