Cities in State of Illinois, United States ( 474 )
- Robbins, Illinois
- Robinson, Illinois
- Rochelle, Illinois
- Rochester, Illinois
- Rock Falls, Illinois
- Rock Island, Illinois
- Rockford, Illinois
- Rockton
- Rolling Meadows
- Romeoville
- Roscoe, Illinois
- Roselle, Illinois
- Rosemont, Illinois
- Rosewood Heights
- Round Lake Beach
- Round Lake Heights
- Round Lake, Illinois
- Round Lake Park
- Rushville, Illinois
- Saint Charles, Illinois
- Saint Joseph, Illinois
- Salem, Illinois
- Sandwich, Illinois
- Sauk Village
- Savanna, Illinois
- Savoy, Illinois
- Schaumburg, Illinois
- Schiller Park, Illinois
- Scott Air Force Base
- Shelbyville, Illinois
- Sherman, Illinois
- Shiloh, Illinois
- Shorewood, Illinois
- Silvis
- Skokie
- Sleepy Hollow, Illinois