- Abington
- Adams
- Addison
- Addison township
- Adkins
- Aetna
- Afton
- Albany
- Albany Township
- Alden Township
- Aledo
- Alexis
- Alexis
- Algonquin
- Algonquin Township
- Allin
- Alma
- Alpha
- Alsip
- Alto Pass
- Alton
- Amboy
- Amboy township
- Amity
- Andalusia
- Andalusia Township
- Andover Township
- Anna
- Annawan
- Annawan township
- Antioch
- Antioch township
- Apple Canyon Lake
- Apple River
- Arbury Hills
- Arlington Heights
- Armstrong
- Aroma
- Aroma Park
- Artesia
- Ash Grove
- Ashkum
- Ashkum Township
- Ashley
- Ashley Township
- Ashton
- Ashton Township
- Atlanta
- Atlanta Township
- Atwood
- Aurora
- Aurora Township
- Aux Sable
- Ava
- Avon
- Ayers