Niagara Gorge, Natural canyon between Ontario and New York.

Niagara Gorge is an 11 km canyon cut by the Niagara River along the Canada–United States border, from the base of Niagara Falls to the Niagara Escarpment near Queenston, Ontario. Its walls expose layered Lockport dolomite above softer rock, and the river runs through a narrow channel with rapids and white foam.

The falls that carved the gorge stood near Queenston, Ontario, about 12,500 years ago. They have since retreated 11 km upstream toward Lake Erie, because water erodes the hard Lockport dolomite of the escarpment top slowly but the softer layers beneath it quickly. In 1883 Matthew Webb, the first person to swim the English Channel, drowned trying to swim the gorge's rapids.

The gorge's name comes from the Niagara River, whose name is often traced to an Iroquoian word for the thunder of the falls. Today commercial jetboats carry visitors through the rapids from Niagara-on-the-Lake, Lewiston and Youngstown, and in midsummer from the Niagara Glen Nature Centre. The 1980 film Superman II includes a scene in which Lois Lane falls into the river here.

The gorge runs 11 km from the base of Niagara Falls to Queenston, Ontario. Kayaking is generally prohibited because of the current, but commercial jetboat tours run from Niagara-on-the-Lake, Lewiston and Youngstown, and in midsummer from Niagara Glen Nature Centre on the Niagara Parkway. Trails along the rim are steep in places, so wear sturdy footwear.

The gorge's current is among the most powerful of any river, so kayaking is generally prohibited; only on isolated occasions have world-class experts been allowed to run the rapids. Matthew Webb, the first person to swim the English Channel, drowned here in 1883 during a publicity stunt. Commercial jetboat tours now carry visitors through the rapids from Niagara-on-the-Lake, Lewiston, Youngstown and, in midsummer, the Niagara Glen Nature Centre.