Peterborough is a city in Ontario, Canada, located approximately 125 kilometres northeast of Toronto and serving as the county seat of Peterborough County. According to the 2021 Census, the city proper had a population of 83,651 residents. The broader Peterborough Census Metropolitan Area, which encompasses the surrounding townships of Selwyn, Cavan Monaghan, Otonabee-South Monaghan, and Douro-Dummer, had a population of 128,624 in 2021, making it the 32nd largest census metropolitan area among Canada's 41 such areas.
The city is governed by Mayor Jeff Leal as of the most recent available information. As the county seat, Peterborough serves as an administrative and regional center for the surrounding area.