Ashby is a city in northeastern Grant County, Minnesota, United States. The population was 469 at the 2020 census. Ashby was platted in 18…Ashby is a city in northeastern Grant County, Minnesota, United States. The population was 469 at the 2020 census. Ashby was platted in 1879, and named for Gunder Ash, an early Norwegian settler. To this day, roughly half the city's population is of Norwegian heritage. A post office has been in operation at Ashby since 1880.