If you are an American citizen and wish to cross over to the Canadian bank of the Niagara River, you are required to show your passport at the border crossing.

Whether you need a passport at Niagara Falls depends entirely on which side of the border you intend to visit and your nationality. If you stay within the United States (Niagara Falls, NY) and you are a U.S. citizen, no passport is required for domestic travel. Similarly, if you stay within Canada (Niagara Falls, ON) as a Canadian citizen, no passport is needed. However, if you wish to cross the Rainbow Bridge or the Whirlpool Bridge to see the "other side," you are crossing an international border. In 2026, U.S. and Canadian citizens must present a valid Passport, Passport Card, or Enhanced Driver's License (EDL) to clear customs. For all other international nationalities, a valid passport and potentially a visa (e-TA for Canada or ESTA for the US) are mandatory to cross. Even for boat tours like the "Maid of the Mist" (US) or "Niagara City Cruises" (Canada), you do not technically cross the border as long as the boat stays within its territorial waters, so you only need a passport if you physically disembark in the other country.