Starting March 15, new regulations will come into effect for travel to Canada requiring the completion of an Electronic Travel Authorization (eTA). The eTA is inexpensive and can be completed online, but must be completed prior to arrival. The system brings Canada in line with the US which operates ESTA (Electronic System for Travel Authorization) for visa-exempt travelers.
The Canadian policy does not apply to US citizens, who will continue to be able to travel to Canada without a visa or eTA. Additionally, if a traveler to Canada requires and obtains a visa, the eTA is not required.
More information including the online application is available at: www.cic.gc.ca/english/visit/eta.asp