- Keenes
- Keensburg
- Keithsburg
- Kempton
- Kenney
- Kewanee
- Keyesport
- Kildeer
- Kingston Mines
- Kinmundy
- Kinsman
- Kingman
- Knollwood Estates Mobile Home Park
- King Island
- Kemper
- Kaolin
- Kellyville
- Kaneland Estates
- Kempster Island
- Kings Mill
- Knoll Creek West
- Koops Island
- Koster
- Kensington
- Kensington Club
- Kentland
- King Acres
- Kings Park
- Kingstone Hills
- Knob Hill