A
- (Parry Sound District) Axe Lake
- (Nipissing District) Aylen Lake
- (Ottawa) Aylmer Island
- (Rainy River District) Aylsworth
- (Regional Municipality of Waterloo) Ayr
- (Grey County) Ayton
- (Bruce County) Arran-Elderslie
- (Lanark County) Ashton
- (Simcoe County) Anten Mills
- (Simcoe County) Amigo Beach
- (Rainy River District) Atikokan
- Aylmer
- Arnprior
- (Simcoe County) Angus
- (Simcoe County) Alliston
- Aurora
- Ajax