Sudbury, officially the City of Greater Sudbury, is the largest city in Northern Ontario by population, with a population of 166,004 at the 2021 Canadian Census. By land area, it is the largest in Ontario and the fifth largest in Canada. It is administratively a single-tier municipality and thus is not part of any district, county, or regional municipality. The City of Greater Sudbury is separate from, but entirely surrounded by the Sudbury District.