Whether you need a visa to visit the Canadian side of Niagara Falls depends entirely on your citizenship and the legal documentation you hold. If you are a United States citizen, you do not need a visa to enter Canada for tourism; however, you must present a valid U.S. passport, passport card, or an Enhanced Driver's License (EDL) to cross the border. If you are a U.S. Permanent Resident (Green Card holder), you also do not need a visa, but you must carry your Green Card and a valid passport from your country of citizenship. For international travelers from countries like the UK, Australia, or many EU nations, a visa is not required, but you must apply for an Electronic Travel Authorization (eTA) before arriving by air; notably, if you are crossing the land border from the U.S. side (like at the Rainbow Bridge), you generally do not need an eTA. However, citizens from "visa-required" countries (such as India, China, or many nations in Africa and the Middle East) must obtain a standard Visitor Visa (TRV) from the Canadian government regardless of whether they are entering by land or air. It is critical to check the current requirements for your specific nationality before you arrive at the border to avoid being turned away at the bridge.