US State Department/Visting canada
Visas are not required for U.S. citizens entering Canada from the U.S. You will, however, need:
(1) proof of your U.S. citizenship such as your U.S. passport (For information on obtaining a U.S. passport, check with one of the regional passport agencies located throughout the U.S.) or certified copy of your birth certificate issued by the city, county or state in the U.S. where you were born. If you are a naturalized U.S. citizen and do not have a passport, you should travel with your naturalization certificate. A driver’s license or Social Security card is NOT valid proof of citizenship.
(2) photo identification, such as a current, valid driver’s license.
All U.S. citizens entering Canada from a third country must have a valid passport.