Rochester is a city in and the county seat of Olmsted County, Minnesota, United States. Located on rolling bluffs on the Zumbro River's south fork in Southeast Minnesota, the city is the home and birthplace of Mayo Clinic. At the 2020 census, the city had a population of 121,395, making it Minnesota's third-largest city. The Rochester metropolitan area, which also includes the nearby rural agricultural areas, had a population of 226,329 in 2020.