| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Roaches | city | Illinois | United States | 38.33 | -89.08 | 830 | |
| Roachtown | city | Illinois | United States | 38.46 | -90.04 | 830 | |
| Roanoke | city | Illinois | United States | 40.80 | -89.20 | 830 | |
| Robbins | city | Illinois | United States | 41.64 | -87.70 | 830 | |
| Robbs | city | Illinois | United States | 37.46 | -88.70 | 403 | |
| Robein | city | Illinois | United States | 40.69 | -89.51 | 830 | |
| Robert Brooks Homes | city | Illinois | United States | 41.87 | -87.66 | 830 | |
| Robert Taylor Homes (historical) | city | Illinois | United States | 41.81 | -87.63 | 830 | |
| Roberts | city | Illinois | United States | 40.61 | -88.18 | 830 | |
| Robinson | city | Illinois | United States | 39.01 | -87.74 | 830 | |
| Robinwood | city | Illinois | United States | 37.58 | -88.91 | 830 | |
| Roby | city | Illinois | United States | 39.74 | -89.40 | 830 | |
| Rochelle | city | Illinois | United States | 41.92 | -89.07 | 830 | |
| Rochester | city | Illinois | United States | 39.75 | -89.53 | 830 | |
| Rochester | city | Illinois | United States | 38.35 | -87.83 | 377 | |
| Rock | city | Illinois | United States | 37.41 | -88.62 | 830 | |
| Rock City | city | Illinois | United States | 42.41 | -89.47 | 898 | |
| Rock Creek | city | Illinois | United States | 37.54 | -88.23 | 830 | |
| Rock Creek | city | Illinois | United States | 40.05 | -91.40 | 830 | |
| Rock Falls | city | Illinois | United States | 41.78 | -89.69 | 830 | |
| Rock Grove | city | Illinois | United States | 42.46 | -89.51 | 898 | |
| Rock Island | city | Illinois | United States | 41.51 | -90.58 | 830 | |
| Rock Run Park | city | Illinois | United States | 41.48 | -88.18 | 830 | |
| Rockbridge | city | Illinois | United States | 39.27 | -90.20 | 830 | |
| Rockdale | city | Illinois | United States | 41.51 | -88.11 | 830 | |
| Rockdale Junction | city | Illinois | United States | 41.56 | -88.11 | 830 | |
| Rockefeller | city | Illinois | United States | 42.27 | -88.00 | 830 | |
| Rockford | city | Illinois | United States | 42.27 | -89.09 | 830 | |
| Rockford Mobile Home Park | city | Illinois | United States | 42.19 | -89.16 | 830 | |
| Rockport | city | Illinois | United States | 39.54 | -91.01 | 830 | |
| Rockton | city | Illinois | United States | 42.45 | -89.07 | 830 | |
| Rockwood | city | Illinois | United States | 37.84 | -89.70 | 390 | |
| Rodden | city | Illinois | United States | 42.33 | -90.32 | 830 | |
| Rodemich | city | Illinois | United States | 38.44 | -90.14 | 830 | |
| Rodgersville | city | Illinois | United States | 37.68 | -88.77 | 413 | |
| Rogers Park | city | Illinois | United States | 42.01 | -87.67 | 830 | |
| Rohrer | city | Illinois | United States | 39.53 | -89.96 | 830 | |
| Rokfordas | city | Illinois | United States | 42.27 | -89.09 | 830 | |
| Roland | city | Illinois | United States | 37.93 | -88.26 | 830 | |
| Rolling Glen | city | Illinois | United States | 41.57 | -87.95 | 830 | |
| Rolling Green | city | Illinois | United States | 39.46 | -88.34 | 830 | |
| Rolling Greens Mobile Home Park | city | Illinois | United States | 41.94 | -89.11 | 830 | |
| Rolling Meadows | city | Illinois | United States | 42.08 | -88.01 | 830 | |
| Rollins | city | Illinois | United States | 42.38 | -88.06 | 830 | |
| Rollo | city | Illinois | United States | 41.67 | -88.89 | 830 | |
| Rombury Oaks | city | Illinois | United States | 41.87 | -88.47 | 830 | |
| Rome | city | Illinois | United States | 40.88 | -89.50 | 830 | |
| Romeo | city | Illinois | United States | 41.64 | -88.06 | 830 | |
| Romeoville | city | Illinois | United States | 41.65 | -88.09 | 830 | |
| Rondout | city | Illinois | United States | 42.28 | -87.90 | 830 | |
| Roodhouse | city | Illinois | United States | 39.48 | -90.37 | 830 | |
| Rooks Creek | city | Illinois | United States | 40.88 | -88.70 | 830 | |
| Roots | city | Illinois | United States | 38.02 | -89.97 | 380 | |
| Rosamond | city | Illinois | United States | 39.38 | -89.16 | 830 | |
| Roscoe | city | Illinois | United States | 42.41 | -89.01 | 830 | |
| Rose Hill | city | Illinois | United States | 39.10 | -88.15 | 830 | |
| Rose Hill Farms | city | Illinois | United States | 41.71 | -88.17 | 830 | |
| Rose Lake | city | Illinois | United States | 38.64 | -90.11 | 406 | |
| Rosebud | city | Illinois | United States | 37.28 | -88.58 | 830 | |
| Rosecrans | city | Illinois | United States | 42.47 | -87.95 | 830 | |
| Rosedale | city | Illinois | United States | 39.04 | -90.55 | 830 | |
| Rosedale | city | Illinois | United States | 38.88 | -90.08 | 830 | |
| Roseland | city | Illinois | United States | 41.70 | -87.63 | 830 | |
| Roselle | city | Illinois | United States | 41.98 | -88.08 | 830 | |
| Rosemont | city | Illinois | United States | 42.00 | -87.88 | 830 | |
| Rosemont | city | Illinois | United States | 38.63 | -90.10 | 416 | |
| Roseville | city | Illinois | United States | 40.73 | -90.66 | 830 | |
| Rosewood Heights | city | Illinois | United States | 38.89 | -90.08 | 830 | |
| Rosiclare | city | Illinois | United States | 37.42 | -88.35 | 354 | |
| Roslyn | city | Illinois | United States | 39.23 | -88.38 | 830 | |
| Rossville | city | Illinois | United States | 40.38 | -87.67 | 830 | |
| Rossville Junction | city | Illinois | United States | 40.36 | -87.64 | 830 | |
| Roth | city | Illinois | United States | 37.10 | -89.31 | 328 | |
| Round Grove | city | Illinois | United States | 41.79 | -89.87 | 830 | |
| Round Knob | city | Illinois | United States | 37.25 | -88.74 | 393 | |
| Round Lake | city | Illinois | United States | 42.35 | -88.09 | 830 | |
| Round Lake Beach | city | Illinois | United States | 42.37 | -88.09 | 830 | |
| Round Lake Heights | city | Illinois | United States | 42.38 | -88.10 | 830 | |
| Round Lake Park | city | Illinois | United States | 42.36 | -88.08 | 830 | |
| Round Prairie | city | Illinois | United States | 38.46 | -88.54 | 830 | |
| Rowe | city | Illinois | United States | 40.93 | -88.67 | 830 | |
| Rowell | city | Illinois | United States | 40.07 | -89.03 | 830 | |
| Roxana | city | Illinois | United States | 38.85 | -90.08 | 830 | |
| Roxbury | city | Illinois | United States | 41.70 | -89.04 | 902 | |
| Royal | city | Illinois | United States | 40.19 | -87.97 | 830 | |
| Royal Acres Trailer Park | city | Illinois | United States | 40.52 | -88.98 | 830 | |
| Royal Court | city | Illinois | United States | 42.12 | -87.85 | 830 | |
| Royal Heights | city | Illinois | United States | 38.54 | -90.01 | 830 | |
| Royal Lake Resort | city | Illinois | United States | 38.57 | -89.39 | 830 | |
| Royal Lakes | city | Illinois | United States | 39.11 | -89.96 | 830 | |
| Royal Oaks Mobile Home Park | city | Illinois | United States | 42.25 | -88.35 | 918 | |
| Royal Ridge | city | Illinois | United States | 42.11 | -87.80 | 830 | |
| Royalton | city | Illinois | United States | 37.88 | -89.11 | 383 | |
| Royce Hill | city | Illinois | United States | 41.72 | -88.11 | 830 | |
| Rozenow's Subdivision | city | Illinois | United States | 42.12 | -87.83 | 830 | |
| Rozetta | city | Illinois | United States | 40.94 | -90.86 | 830 |