A
- Aberdeen, Grey County
- Aberdeen, Prescott and Russell County
- Aberfeldy
- Aberfoyle
- Abingdon
- Abitibi
- Abitibi Canyon
- Aboyne
- Acanthus
- Achill
- Achray
- Actinolite
- Acton
- Actons Corners
- Adamsdale
- Adamsville
- Adanac, Nipissing District
- Adanac, Parry Sound District
- Addington
- Addison
- Adelaide-Metcalfe
- Adelard
- Adolphustown
- Advance
- Agawa Bay
- Agerton
- Agincourt
- Ahmic Harbour
- Ahmic Lake
- Aikensville
- Ailsa Craig
- Airlie
- Ajax
- Alban
- Albert
- Alberton
- Albion
- Albuna
- Albury
- Alcona
- Alder
- Alderdale
- Aldershot
- Alderslea
- Alderville
- Aldreds Beach
- Alexandria
- Alfred
- Algoma Mills
- Algonquin
- Alice
- Allan Mills
- Allan Park
- Allanburg
- Allans Corners
- Allen
- Allendale
- Allenford
- Allens Corner
- Allensville
- Allanwater Bridge
- Allenwood
- Allenwood Beach
- Allimil
- Allisonville
- Alliston
- Alloa
- Alma
- Almira
- Almonte
- Alport
- Alsace
- Alsfeldt
- Althorpe
- Alton
- Altona
- Alvanley
- Alvinston
- Amaranth
- Amaranth Station
- Amberley
- Ameliasburgh
- Ameliasburgh Township
- Amesdale
- Amherstburg
- Amherst Pointe
- Amigo Beach
- Amyot
- Amherstview
- Ancaster
- Anderson
- Andrewsville
- Angus
- Angus Glen
- Annable
- Ansnorveldt
- Ansonville
- Anten Mills
- Antrim
- Appleby Corner
- Apple Hill
- Apsley
- Ardbeg
- Arden
- Ardendale
- Ardoch
- Ardtrea
- Ariss
- Arklan
- Arkona
- Arkwright
- Armadale
- Armstrong, Thunder Bay District
- Armstrong Township
- Armstrong Corners
- Armstrong Mills
- Arnprior
- Aroland First Nation
- Arranvale
- Arthur
- Arva
- Ashburn
- Ashby Mills
- Ashgrove
- Ashton
- Ashworth
- Aspdin
- Asselstine
- Assumption
- Astorville
- Athens
- Atherley
- Atherton
- Athol, Prince Edward County
- Athol, Stormont, Dundas and Glengarry United Counties
- Atikokan
- Atironto
- Attawapiskat
- Atwood
- Auden
- Aughrim
- Aurora
- Austin
- Avening
- Avonmore
- Aylen
- Aylen Lake
- Aylen Lake Station
- Aylmer
- Ayr
- Ayton
- Azilda
Read more about this topic: List Of Communities In Ontario