Niagara-on-the-Lake (2001 population 13,839) is a town where the Niagara River meets Lake Ontario in Ontario, Canada. It is located across from Youngstown, New York.

First known as Butlersburg, Niagara-on-the-Lake was incorporated in 1781 as the Town of Newark when Loyalists fled the United States during the American Revolution.

In 1792 the newly renamed Niagara was named the capital of Upper Canada, but lost that distinction to Toronto during the War of 1812. During that war, American forces captured and later destroyed the town before they withdrew. The British rebuilt, however, and today it has retained much of its historical charm.

Niagara-on-the-Lake, said by some to be the prettiest town in Canada, is now a tourist magnet. A lot of the former military sites have been restored, and there are also several wineries in the area. It is the home of the Shaw Festival.