- Kahm
- Kampenville
- Kamps-Stiens Island
- Kampsville
- Kane
- Kaneland Estates
- Kaneville
- Kangley
- Kankakee
- Kansas
- Kaolin
- Kappa
- Karbers Ridge
- Karnak
- Kasbeer
- Kaser
- Kaskaskia
- Kaskaskia Island
- Katy Did
- Kaufman
- Kay - Lou Trailer Courts
- Kay Island
- Kedron
- Keenes
- Keenesville
- Keeneyville
- Keensburg
- Kegley
- Keithsburg
- Kell