Martin County is a county in Minnesota, United States. As of the 2020 census, the population was 20,025. Its county seat is Fairmont.

Minnesota's 1st congressional district extends across southern Minnesota from the border with South Dakota to the border with Wisconsin. It is a primarily rural district built on a strong history of agriculture, though this is changing rapidly due to strong population growth in the Rochester combined statistical area. The district is also home to several of Minnesota's major mid-sized cities, including Rochester, Mankato, Winona, Austin, Owatonna, Albert Lea, Red Wing, New Ulm, Worthington, and Lake City. It is represented by Republican Brad Finstad.