Niagara-on-the-Lake is a town in Ontario, Canada. It is located on the Niagara Peninsula at the point where the Niagara River meets Lake Ontario, across the river from New York, United States. Niagara-on-the-Lake is in the Niagara Region of Ontario and is the only town in Canada that has a lord mayor. It had a population of 19,088 as of the 2021 Canadian census.