| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sublette | city | Illinois | United States | 41.64 | -89.23 | 902 | |
| Sudduth (historical) | city | Illinois | United States | 39.71 | -89.82 | 830 | |
| Sugar Brook | city | Illinois | United States | 41.70 | -88.09 | 830 | |
| Sugar Creek Ranch | city | Illinois | United States | 37.57 | -88.93 | 830 | |
| Sugar Grove | city | Illinois | United States | 40.03 | -90.57 | 830 | |
| Sugar Grove | city | Illinois | United States | 41.76 | -88.44 | 830 | |
| Sugar Grove | city | Illinois | United States | 41.24 | -90.73 | 830 | |
| Sugar Island | city | Illinois | United States | 41.01 | -87.82 | 830 | |
| Sugarloaf Heights | city | Illinois | United States | 38.50 | -90.21 | 830 | |
| Sullivan | city | Illinois | United States | 39.60 | -88.61 | 830 | |
| Sullivan Center (historical) | city | Illinois | United States | 40.92 | -88.30 | 830 | |
| Sulphur Springs | city | Illinois | United States | 41.42 | -88.77 | 830 | |
| Sulphur Springs (historical) | city | Illinois | United States | 37.60 | -88.84 | 830 | |
| Summer Hill | city | Illinois | United States | 39.55 | -90.92 | 830 | |
| Summerdale | city | Illinois | United States | 41.98 | -87.67 | 830 | |
| Summerfield | city | Illinois | United States | 41.56 | -88.21 | 830 | |
| Summerfield | city | Illinois | United States | 38.60 | -89.75 | 830 | |
| Summerhill | city | Illinois | United States | 42.11 | -87.86 | 830 | |
| Summersville | city | Illinois | United States | 38.33 | -88.87 | 830 | |
| Summerville | city | Illinois | United States | 39.19 | -90.12 | 830 | |
| Summit | city | Illinois | United States | 41.79 | -87.81 | 830 | |
| Summit | city | Illinois | United States | 38.55 | -90.00 | 830 | |
| Summum | city | Illinois | United States | 40.27 | -90.28 | 830 | |
| Sumner | city | Illinois | United States | 38.72 | -87.86 | 830 | |
| Sun River Terrace | city | Illinois | United States | 41.13 | -87.74 | 830 | |
| Sunbeam | city | Illinois | United States | 41.13 | -90.74 | 830 | |
| Sunbury | city | Illinois | United States | 41.10 | -88.53 | 830 | |
| Sunfield | city | Illinois | United States | 38.06 | -89.24 | 830 | |
| Sunny Acres | city | Illinois | United States | 42.15 | -87.88 | 830 | |
| Sunny Crest | city | Illinois | United States | 41.54 | -87.69 | 830 | |
| Sunny Hill | city | Illinois | United States | 41.40 | -90.42 | 830 | |
| Sunny Hill | city | Illinois | United States | 39.62 | -90.77 | 830 | |
| Sunny Hill Estates | city | Illinois | United States | 41.40 | -90.43 | 830 | |
| Sunnybrook Meadows | city | Illinois | United States | 39.91 | -91.39 | 830 | |
| Sunnyland | city | Illinois | United States | 40.69 | -89.51 | 830 | |
| Sunnyside | city | Illinois | United States | 41.96 | -87.67 | 830 | |
| Sunnyside | city | Illinois | United States | 42.39 | -88.23 | 830 | |
| Sunnyside | city | Illinois | United States | 37.80 | -89.05 | 403 | |
| Sunnyside | city | Illinois | United States | 42.36 | -89.91 | 898 | |
| Sunridge | city | Illinois | United States | 42.13 | -87.79 | 830 | |
| Sunrise Hills | city | Illinois | United States | 39.23 | -89.61 | 830 | |
| Sunrise Ridge | city | Illinois | United States | 42.38 | -88.37 | 839 | |
| Sunset Court | city | Illinois | United States | 42.12 | -87.79 | 830 | |
| Sunset Fields | city | Illinois | United States | 42.12 | -87.84 | 830 | |
| Sunset Harbor | city | Illinois | United States | 37.62 | -88.93 | 830 | |
| Sunset Hills | city | Illinois | United States | 41.52 | -88.20 | 830 | |
| Sunset Ridge | city | Illinois | United States | 41.56 | -88.19 | 830 | |
| Sunset View Estates | city | Illinois | United States | 42.14 | -87.88 | 830 | |
| Sunset View Mobile Home Park | city | Illinois | United States | 42.41 | -88.61 | 941 | |
| Sunset Villa | city | Illinois | United States | 41.91 | -88.43 | 846 | |
| Surrey | city | Illinois | United States | 40.91 | -90.47 | 830 | |
| Surrey Woods | city | Illinois | United States | 41.92 | -88.29 | 830 | |
| Sutter | city | Illinois | United States | 40.28 | -91.34 | 830 | |
| Sutter | city | Illinois | United States | 40.40 | -89.37 | 830 | |
| Sutton | city | Illinois | United States | 42.10 | -88.19 | 849 | |
| Sutton Point | city | Illinois | United States | 42.13 | -87.88 | 830 |