A
- (Miller County) Alworth
- (Woodruff County) Amenia
- (Marion County) Ament Corners
- (Jeff Davis County) Andalusia Island
- (Marion County) Andres
- (Coffee County) Andrews and Hurds Subdivision
- (Madison County) Appaloosa West
- (Boone County) Apple River Island
- (Marshall County) Appleton
- (Boone County) Argo Fay
- (Bibb County) Argyle
- (Boone County) Arnold
- (Wilcox County) Arpee
- (Coffee County) Arrow Ridge Mobile Home Park
- (Boone County) Ashdale Junction
- (Van Buren County) Askvig Addition
- (Washington County) Atterberry
- (Cherokee County) Augerville
- (Coffee County) Austin
- (Greene County) Aux Sable Island
- (Washington County) Averyville
- (Boone County) Ayers
- (Coffee County) Avanti Ridge
- (Coffee County) Arrowhead
- (Coffee County) Anetsberger's Subdivision
- (Coffee County) Ancient Tree
- (Marion County) Anand Brook
- (Marion County) Aspen Meadows
- (Marion County) Arbor Settlement
- (Marion County) Arbor Creek