- Aaronsburg
- Abbottstown
- Abington
- Ackermanville
- Acme
- Acosta
- Adah
- Adamsburg
- Adamstown
- Adamsville
- Addison
- Adrian
- Airville
- Akron
- Alba
- Albion
- Albrightsville
- Alburtis
- Aldan
- Aldenville
- Aleppo
- Alexandria
- Aliquippa
- Allenport
- Allensville
- Allentown
- Allenwood
- Allison
- Allison Park
- Allport
- Altoona
- Alum Bank
- Alverda
- Alverton
- Amberson
- Ambler
- Ambridge
- Amity
- Analomink
- Ancient Oaks
- Andalusia
- Andreas
- Anita
- Annandale
- Annville
- Antes Fort
- Apollo
- Aquashicola
- Arcadia
- Archbald
- Arcola
- Ardara
- Ardmore
- Arendtsville
- Aristes
- Arlington Heights
- Armagh
- Armbrust
- Armstrong
- Arnold
- Arnot
- Arona
- Arsenal
- Artemas
- Ashfield
- Ashland
- Ashley
- Ashville
- Aspers
- Aspinwall
- Atglen
- Athens
- Atlantic
- Atlasburg
- Auburn
- Audubon
- Aultman
- Austin
- Avalon
- Avella
- Avis
- Avoca
- Avondale
- Avonmore
