Many nationalities do not require a visa to visit Canada. These include:
Andorra, Antigua and Barbuda, Australia, Austria, Bahamas, Barbados, Belgium, Botswana, Brunei, Croatia, Cyprus, Denmark, Estonia, Finland, France, Germany, Greece, Holy See, Hong Kong, Hungary, Iceland, Ireland, Israel (National Passport holders only), Italy, Japan, Korea (Republic of), Latvia (Republic of), Lithuania, Liechtenstein, Luxembourg, Malta, Monaco, Namibia, Netherlands, New Zealand, Norway, Papua New Guinea, Poland, Portugal, St. Kitts and Nevis, St. Lucia, St. Vincent, San Marino, Singapore, Slovakia, Solomon Islands, Spain, Swaziland, Sweden, Slovenia, Switzerland, Taiwan, United States, and Western Samoa.
Holders of a United states green card can also enter without a visa.
Canada Visa information
Canadian embassies and consulates
Foreign embassies and consulates in Canada