New Ulm ( NEW ULM) is a city in Brown County, Minnesota, United States. The population was 14,120 at the 2020 census. It is the count…New Ulm ( NEW ULM) is a city in Brown County, Minnesota, United States. The population was 14,120 at the 2020 census. It is the county seat of Brown County. It is located on the triangle of land formed by the confluence of the Minnesota River and the Cottonwood River.