- Astrid Dora Janson
- Astronomy
- Astrophysics
- Aszure Barton
- Atanarjuat (The Fast Runner)
- Atelier TAG
- Athabasca
- Athabasca Landing
- Athabasca Landing Trail
- Athabasca Pass
- Athabasca River
- Athabasca River
- Athabasca University
- Atheism and Agnosticism
- Athol Murray College of Notre Dame
- Atikamekw
- Atikokan
- Atlantic Campaign of the War of 1812
- Atlantic Canadian Composers' Association/Association des Compositeurs Canadiens de l'Atlantique
- Atlantic City
