With St. Catharines, Ontario and Niagara Falls in this area, 1.5 million people live within 45 kilometers of Buffalo, New York
I think you mean to ask, "How far is Niagara-on-the-lake from Niagara Falls." If that is the question, then it is about 26 kilometers.
Niagara falls is in New York.However, if you mean New York, the city, then the distance is about 495 kilometers.
Niagara Falls has eroded 11.4 kilometers (7.1 miles) during the last 12,300 years.
The Niagara Gorge extends from the Horseshoe Falls for 11 kilometers (7 miles) downstream to the beginning of the Niagara Escarpment at Queenston - Lewiston.
Niagara falls ========== In addition to Niagara Falls, there are also some much smaller falls on the Canada-US border in Quetico Provincial Park. There are three falls at Niagara. Two of them are in the USA. The Horseshoe Falls, the most spectacular of the three, is almost entirely within Canada.
570 km
about 420 kilometers
660 km
Niagara falls is along the Niagara RiverNiagara Falls is on the Niagara River.
It is 154 kilometers according to Google Maps.
That is merely an opinionated question. Many people have different opinions on Niagara Falls.