US VISITORS TO ONTARIO
All persons, including U.S. citizens, travelling by air between the United States and Canada (including in transit passengers who are transferring planes in the U.S.) are required to present a valid passport or NEXUS card, according to an American law, the Western Hemisphere Travel Initiative (WHTI).
WHTI requirements state that all US citizens must present a passport book, passport card, or other WHTI-compliant document for entry into the U.S. by land and water. Children under age 16 will be able to continue crossing land and sea borders using only a U.S. birth certificate or other form of U.S. citizenship such as a naturalization certificate. The Department of Homeland Security provides more information on travel requirements.
All Canadian citizens, including dual citizens, will need a valid Canadian passport to travel to Canada by air.
ALL OTHER VISITORS TO ONTARIO
Citizens of other countries, except Greenland, and residents of St-Pierre and Miquelon, must have a valid passport. Visitors from some countries also require a visitor's visa. Visit the Citizenship and Immigration Canada website for a complete list of countries whose citizens require visas to enter Canada.
As of November 10, 2016, all via-exempt travellers will be required to obtain an eTA (Electronic Travel Authorization) to board their flight to Canada.
Travellers under the age of 18 and unaccompanied by a parent need a letter of permission to travel in Canada from a parent or guardian.
CUSTOMS AND DUTY FREE
Locate your nearest customs office at the Border Information Service (BIS) .
The Canadian Food Inspection Agency provides information on what agricultural items are restricted or prohibited entry to Canada. Learn more about customs information for visitors to Ontario at Canada International, at Canada Border Services Agency and at the Citizenship and Immigration Canada.
Get the details on bringing alcoholic and tobacco products to Canada at Canada Border Services Agency (CBSA).
Learn more about duty-free allowances for returning residents of Canada.
More information about entering or re-entering the U.S. is available through U.S. Customs for returning residents of the U.S.