- Association for Canadian Studies
- Association of Canadian Choral Communities
- Association of Canadian Orchestras/Association des orchestres canadiens
- Association of Canadian Women Composers/Association des femmes compositeurs canadiennes
- Association of Canadian Women Composers/L'Association des femmes compositeurs canadiennes
- Association of Universities and Colleges of Canada
- Associations
- Aster
- Asthma
- Astral Media
- Astrid Dora Janson
- Astronomy
- Astrophysics
- Aszure Barton
- Atanarjuat (The Fast Runner)
- Atelier TAG
- Athabasca
- Athabasca Landing
- Athabasca Landing Trail
- Athabasca Pass
