- Abington
- Adams
- Addison township
- Addison
- Adkins
- Aetna
- Afton
- Albany Township
- Albany
- Alden Township
- Aledo
- Alexis
- Alexis
- Algonquin Township
- Algonquin
- Allin
- Alma
- Alpha
- Alsip
- Altamont
- Alto Pass
- Alto Pass Precinct
- Alton
- Alvin
- Amboy
- Amboy township
- Andalusia
- Andalusia Township
- Andover Township
- Anna
- Annapolis
- Annawan
- Annawan township
- Antioch township
- Antioch
- Apple Canyon Lake
- Apple River
- Apple River Township
- Arbury Hills
- Arcola Township
- Arcola
- Argenta
- Arlington Heights
- Aroma
- Aroma Park
- Arrington
- Artesia
- Arthur
- Ash Grove
- Ash Grove
- Ashkum
- Ashkum Township
- Ashley Township
- Ashley
- Ashmore Township
- Ashmore
- Ashton Township
- Ashton
- Assumption Township
- Assumption
- Atkinson
- Atkinson township
- Atlanta Township
- Atlanta
- Atwood
- Aurora Township
- Aurora
- Aux Sable
- Ava
- Avena
- Avon
- Ayers