- Adams
- Addison
- Addison township
- Aetna
- Afton
- Albany
- Albany Township
- Alden Township
- Algonquin
- Algonquin Township
- Allen
- Alsip
- Amboy
- Amboy township
- Antioch
- Antioch township
- Apple Canyon Lake
- Apple River
- Arcola
- Arcola Township
- Argyle
- Arispie
- Arlington Heights
- Armington
- Armstrong
- Aroma
- Aroma Park
- Arrowsmith
- Arrowsmith Township
- Artesia
- Ash Grove
- Ashkum
- Ashkum Township
- Ashton
- Ashton Township
- Atlanta
- Atlanta Township
- Atwood
- Augusta
- Augusta Township
- Aurora
- Aurora Township
- Aux Sable
- Avon
- Ayers