Kandiyohi County is a county located in the U.S. state of Minnesota. As of the 2010 census, its population was 42,239. Its county seat is Willmar.Kandiyohi County comprises the Willmar, MN Micropolitan Statistical Area.HistoryKandiyohi County is named after a Dakota word meaning "where the buffalo fish come" (kandi’ - the buffalo fish + oh-hi’-yu - v. of hiyu - to come through). Kandiyohi County was organized in 1858 with its county seat in Kandiyohi, which was then called Kandiyohi Station and was just a railroad stop. The original county occupied only the southern half of its current area. Development was slow, and in 1870 the state legislature called for Monongalia County to merge with Kandiyohi and make one larger county. It took until 21 November 1871 to agree on the centrally-located Willmar as the county seat.