Canadians can travel to visa-free to many countries, but increasingly an Electronic Travel Authorization (ETA) is required to enter a country. It is usually done through a website or an app. Sometimes these can be completed on arrival (as I did in Taiwan), but it is best to do in advance. Typically this is to be done within 72 hours of arrival but no earlier. Here is a list of countries requiring ETAs as of January 1, 2025.
Asia
Bahrain
India
Jordan
Oman
Qatar
Malaysia
Maldives
Myanmar
Singapore
Sri Lanka
Taiwan
Turkey
United Arab Emirates
Africa
Egypt
Ethiopia
Kenya
Madagascar
Tanzania
Oceania
Australia
New Zealand
Europe
United Kingdom
EU countries - Schengen (Austria, Belgium, Bulgaria, Croatia, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and Switzerland)