Niagara, Ontario may refer to:
Niagara-on-the-Lake, formerly called Niagara, a town that was at the mouth of the Niagara River Niagara Falls, Ontario, a city located adjacent to Niagara Falls Niagara Peninsula, a peninsula located between Lake Ontario and Lake Erie Regional Municipality of Niagara, also called Niagara Region, a regional municipality located on the Niagara Peninsula
See also Niagara (disambiguation)