The American Falls of Niagara, as seen from the Canadian side September 19, 2002. The tour boat Maid of the Mist is in the river below, Bridal Veil Falls is the small separate falls on the right, and the city of Niagara Falls, New York is in the background.

The American Falls is one of three waterfalls that together are known as Niagara Falls on the Niagara River along the Canada-U.S. border. Unlike the wider Horseshoe Falls, which is shared between the United States and Canada, American Falls is completely within the U.S. state of New York.

The falls receive approximately 10% of the flow from Niagara River, with most of the rest going over Horseshoe Falls, from which it is separated by Goat Island. It has a straight line crest width of about 253 m (830 feet). If measured along the jagged lip of the falls, the crest is about 290 m (950 feet) long. The torrent of water passing over the crest of the falls is about 0.6 m (2 feet) deep.

The falls are viewable from a steep angle on the American side, where it is possible to approach to within several meters of the edge of the falls. One can view the falls from the bank of the river, as well as on Goat Island, which is accessible by a pedestrian bridge that crosses the rapids of the Niagara river upstream from the falls. The falls are viewable head-on from the Canadian side in Niagara Falls, Ontario.