| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Solar Grove | city | Illinois | United States | 42.12 | -87.84 | 830 | |
| Sollitt | city | Illinois | United States | 41.29 | -87.63 | 830 | |
| Solomon | city | Illinois | United States | 40.25 | -88.82 | 830 | |
| Solon Mills | city | Illinois | United States | 42.44 | -88.27 | 830 | |
| Somerfield | city | Illinois | United States | 41.67 | -88.14 | 830 | |
| Somerset | city | Illinois | United States | 37.65 | -88.46 | 406 | |
| Somerset Hills | city | Illinois | United States | 41.63 | -87.92 | 830 | |
| Sometimes referred to as Hopper's Mill. | city | Illinois | United States | 40.79 | -90.99 | 830 | |
| Somonauk | city | Illinois | United States | 41.63 | -88.68 | 830 | |
| Sonora (historical) | city | Illinois | United States | 40.49 | -91.35 | 830 | |
| Soperville | city | Illinois | United States | 41.01 | -90.40 | 830 | |
| Sorento | city | Illinois | United States | 39.00 | -89.57 | 830 | |
| South Addison | city | Illinois | United States | 41.91 | -87.99 | 830 | |
| South Barrington | city | Illinois | United States | 42.09 | -88.12 | 849 | |
| South Beloit | city | Illinois | United States | 42.49 | -89.04 | 830 | |
| South Bluff Homes | city | Illinois | United States | 42.49 | -89.05 | 830 | |
| South Branch Addition | city | Illinois | United States | 41.85 | -87.64 | 830 | |
| South Brighton | city | Illinois | United States | 41.82 | -87.69 | 830 | |
| South Chicago | city | Illinois | United States | 41.72 | -87.54 | 830 | |
| South Chicago Heights | city | Illinois | United States | 41.48 | -87.64 | 830 | |
| South Chicago Heights | city | Illinois | United States | 41.73 | -87.56 | 830 | |
| South Commons | city | Illinois | United States | 41.84 | -87.62 | 830 | |
| South Crest | city | Illinois | United States | 39.90 | -91.39 | 830 | |
| South Danville | city | Illinois | United States | 40.12 | -87.64 | 830 | |
| South Deering | city | Illinois | United States | 41.69 | -87.56 | 830 | |
| South Edgewater | city | Illinois | United States | 41.97 | -87.66 | 830 | |
| South Elgin | city | Illinois | United States | 41.99 | -88.29 | 830 | |
| South Elkhorn | city | Illinois | United States | 41.97 | -89.71 | 830 | |
| South Elmhurst | city | Illinois | United States | 41.88 | -87.94 | 830 | |
| South Englewood | city | Illinois | United States | 41.75 | -87.66 | 830 | |
| South Evanston | city | Illinois | United States | 42.04 | -87.68 | 830 | |
| South Freeport | city | Illinois | United States | 42.24 | -89.57 | 830 | |
| South Harvey | city | Illinois | United States | 41.58 | -87.66 | 830 | |
| South Holland | city | Illinois | United States | 41.60 | -87.61 | 830 | |
| South Jacksonville | city | Illinois | United States | 39.71 | -90.23 | 830 | |
| South Kenwood | city | Illinois | United States | 41.77 | -87.58 | 830 | |
| South Lawndale | city | Illinois | United States | 41.84 | -87.71 | 830 | |
| South Lockport | city | Illinois | United States | 41.57 | -88.05 | 830 | |
| South Lynn | city | Illinois | United States | 41.78 | -87.68 | 830 | |
| South Ottawa (historical) | city | Illinois | United States | 41.33 | -88.84 | 830 | |
| South Park | city | Illinois | United States | 41.74 | -88.30 | 830 | |
| South Park Terrace | city | Illinois | United States | 39.91 | -91.40 | 830 | |
| South Paw Paw | city | Illinois | United States | 41.66 | -88.94 | 830 | |
| South Pekin | city | Illinois | United States | 40.49 | -89.65 | 830 | |
| South Pole | city | Illinois | United States | 41.68 | -87.56 | 830 | |
| South Rome | city | Illinois | United States | 40.85 | -89.54 | 830 | |
| South Roxana | city | Illinois | United States | 38.83 | -90.06 | 830 | |
| South Shore | city | Illinois | United States | 41.76 | -87.58 | 830 | |
| South Strasburg | city | Illinois | United States | 39.35 | -88.62 | 830 | |
| South Streator | city | Illinois | United States | 41.12 | -88.83 | 830 | |
| South Wilmington | city | Illinois | United States | 41.17 | -88.28 | 830 | |
| Southbridge Commons | city | Illinois | United States | 42.11 | -87.83 | 830 | |
| Southbury | city | Illinois | United States | 41.68 | -88.33 | 830 | |
| Southern Hills | city | Illinois | United States | 37.70 | -89.21 | 830 | |
| Southern View | city | Illinois | United States | 39.90 | -91.40 | 830 | |
| Southern View | city | Illinois | United States | 39.76 | -89.65 | 830 | |
| Southgate | city | Illinois | United States | 41.89 | -89.06 | 830 | |
| Southgate Estates Trailer Park | city | Illinois | United States | 40.45 | -88.99 | 856 | |
| Southgate Park | city | Illinois | United States | 41.67 | -88.14 | 830 | |
| Southland Acres | city | Illinois | United States | 39.79 | -88.28 | 830 | |
| Southlawn | city | Illinois | United States | 39.75 | -89.62 | 830 | |
| Southmoor | city | Illinois | United States | 38.93 | -90.20 | 830 | |
| Southmoor | city | Illinois | United States | 41.65 | -87.83 | 830 | |
| Southmore Heights | city | Illinois | United States | 39.05 | -88.75 | 830 | |
| Southport | city | Illinois | United States | 40.79 | -89.90 | 830 |