Twin Cities of Niagara Falls: New York (USA) and Ontario (Canada)

The closest city to Niagara Falls depends on which side of the border you're on—because they are twin cities with the same name:

• Niagara Falls, New York (USA) – directly across the river from…
• Niagara Falls, Ontario (Canada) – the Canadian counterpart.

They are separated only by the Niagara River and connected by the Rainbow Bridge (vehicles/pedestrians) and the Whirlpool Rapids Bridge (vehicles). Each is the other's nearest urban center.