King's Highway 115, commonly referred to as Highway 115, is a provincially maintained highway in the Canadian province of Ontario that connects Peterborough with Toronto via Highway 401. The highway begins at a junction with Highway 401 southwest of Newcastle and ends at an at-grade intersection with Highway 7 east of Peterborough.

Peterborough is a city on the Otonabee River in Ontario, Canada, about 125 kilometres northeast of Toronto. According to the 2021 Census, the population of the City of Peterborough was 83,651. The population of the Peterborough Census Metropolitan Area (CMA), which includes the surrounding Townships of Selwyn, Cavan Monaghan, Otonabee-South Monaghan, and Douro-Dummer, was 128,624 in 2021. In 2021, Peterborough ranked 32nd among the country's 41 census metropolitan areas according to the CMA in Canada. The current mayor of Peterborough is Jeff Leal.