Lancaster is a city in Kittson County, Minnesota, United States. As of the 2020 census, the city population was 364. Lancaster was incorporate…Lancaster is a city in Kittson County, Minnesota, United States. As of the 2020 census, the city population was 364. Lancaster was incorporated in 1904 along a Soo Line Railroad line running from Glenwood to the Canada–US border. The city was named after a railroad official believed to have come from Lancashire County in England.