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