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