Mercer County is located in the northwest corner of Missouri and is part of the St. Joseph, MO-KS Metropolitan Statistical Area. The county seat is Princeton. The county was organized in 1845.

The county is governed by a three-member county commission, elected in November of each year. Other elected officials include a sheriff, prosecuting attorney, assessor, collector, and public administrator.

The county is part of the North Central Missouri Regional Council of Governments, which provides services such as economic development, regional planning, and grant writing.

The county is served by the Mercer County R-III School District, which includes Princeton Elementary School, Mercer Middle School, and Princeton High School.

The county is home to several state parks, including Big Lake State Park, Grand Pass Conservation Area, and Thousand Hills State Park.

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