Niagara Falls is a city in Niagara Regional Municipality, in southeastern Ontario, Canada.

It is a port on the Niagara River opposite Niagara Falls, New York.

The city overlooks a cataract of Niagara Falls known as Horseshoe Falls or Canadian Falls; the crescent-shaped cataract is 57 m (187 ft) high and carries nine times more water than its United States counterpart.

Niagara Falls is an enormously popular tourist destination, and it is also a major source of electricity for Ontario.

The city is connected to the U. S. side of the falls by several bridges, including the Rainbow and Whirlpool bridges.

Originally called Elgin, the community merged with Clifton in 1856 and was known as Clifton until 1881, when its name changed to Niagara Falls. It incorporated as a city in 1904, and in 1963, the city greatly expanded when it merged with Stamford Township.

Niagara Falls has continued to grow commercially and culturally, in part due to its flourishing tourist industry.