| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Loami | city | Illinois | United States | 39.68 | -89.85 | 830 | |
| Lochanora | city | Illinois | United States | 42.24 | -88.09 | 895 | |
| Lockhaven | city | Illinois | United States | 38.94 | -90.29 | 830 | |
| Lockport | city | Illinois | United States | 41.59 | -88.06 | 830 | |
| Lockport Heights | city | Illinois | United States | 41.62 | -88.02 | 830 | |
| Locks | city | Illinois | United States | 41.84 | -87.66 | 830 | |
| Locust Grove (historical) | city | Illinois | United States | 37.87 | -88.74 | 830 | |
| Loda | city | Illinois | United States | 40.52 | -88.07 | 830 | |
| Lodemia | city | Illinois | United States | 40.81 | -88.57 | 830 | |
| Lodge | city | Illinois | United States | 40.11 | -88.56 | 830 | |
| Log Cabin Camp | city | Illinois | United States | 41.16 | -87.58 | 830 | |
| Logan | city | Illinois | United States | 37.96 | -88.84 | 830 | |
| Logan | city | Illinois | United States | 39.74 | -87.61 | 830 | |
| Logan Square | city | Illinois | United States | 41.92 | -87.70 | 830 | |
| Logansburgh (historical) | city | Illinois | United States | 38.34 | -87.89 | 830 | |
| Logansport (historical) | city | Illinois | United States | 38.11 | -88.42 | 830 | |
| Lomax | city | Illinois | United States | 40.68 | -91.07 | 830 | |
| Lombard | city | Illinois | United States | 41.88 | -88.01 | 830 | |
| Lombard Tree | city | Illinois | United States | 41.88 | -87.72 | 830 | |
| Lombardville | city | Illinois | United States | 41.22 | -89.66 | 830 | |
| London Mills | city | Illinois | United States | 40.71 | -90.27 | 830 | |
| Lone Tree | city | Illinois | United States | 40.84 | -91.02 | 830 | |
| Lone Tree Corners | city | Illinois | United States | 41.18 | -89.49 | 830 | |
| Lone Tree Subdivision | city | Illinois | United States | 42.14 | -87.87 | 830 | |
| Lonesome Acres | city | Illinois | United States | 42.18 | -89.02 | 830 | |
| Long Branch | city | Illinois | United States | 37.89 | -88.58 | 830 | |
| Long Branch | city | Illinois | United States | 40.22 | -90.04 | 830 | |
| Long Creek | city | Illinois | United States | 39.81 | -88.85 | 830 | |
| Long Grove | city | Illinois | United States | 42.18 | -88.00 | 830 | |
| Long Grove Valley | city | Illinois | United States | 42.17 | -88.05 | 830 | |
| Long Lake | city | Illinois | United States | 42.37 | -88.13 | 830 | |
| Long Point | city | Illinois | United States | 41.00 | -88.89 | 830 | |
| Long Run Acres | city | Illinois | United States | 41.64 | -88.00 | 830 | |
| Long Run Creek | city | Illinois | United States | 41.64 | -87.99 | 830 | |
| Long Shore Park | city | Illinois | United States | 40.76 | -89.56 | 830 | |
| Longview | city | Illinois | United States | 39.89 | -88.07 | 830 | |
| Longview Estates | city | Illinois | United States | 41.95 | -88.34 | 830 | |
| Longview Place | city | Illinois | United States | 39.85 | -88.95 | 830 | |
| Loogootee | city | Illinois | United States | 38.90 | -88.85 | 830 | |
| Loon Lake | city | Illinois | United States | 42.45 | -88.09 | 830 | |
| Loose Pulley Junction | city | Illinois | United States | 42.13 | -89.22 | 830 | |
| Loraine | city | Illinois | United States | 40.15 | -91.22 | 830 | |
| Loran | city | Illinois | United States | 42.24 | -89.91 | 830 | |
| Lorenzo | city | Illinois | United States | 41.35 | -88.22 | 830 | |
| Loretto | city | Illinois | United States | 40.98 | -88.43 | 830 | |
| Lori-Sue Subdivision | city | Illinois | United States | 41.34 | -88.40 | 830 | |
| Lost Nation | city | Illinois | United States | 41.91 | -89.37 | 830 | |
| Lostant | city | Illinois | United States | 41.14 | -89.06 | 830 | |
| Lotus | city | Illinois | United States | 40.32 | -88.46 | 830 | |
| Lotus Woods | city | Illinois | United States | 42.42 | -88.17 | 830 | |
| Louisville | city | Illinois | United States | 38.77 | -88.50 | 830 | |
| Love | city | Illinois | United States | 41.57 | -89.81 | 830 | |
| Loveland's Subdivision | city | Illinois | United States | 42.12 | -87.79 | 830 | |
| Loves Corner | city | Illinois | United States | 37.50 | -88.17 | 406 | |
| Loves Park | city | Illinois | United States | 42.32 | -89.06 | 830 | |
| Lovilla | city | Illinois | United States | 38.16 | -88.67 | 830 | |
| Lovington | city | Illinois | United States | 39.72 | -88.63 | 830 | |
| Low Point | city | Illinois | United States | 40.87 | -89.31 | 830 | |
| Lowder | city | Illinois | United States | 39.55 | -89.85 | 830 | |
| Lowell | city | Illinois | United States | 41.25 | -89.01 | 830 | |
| Lower West Side | city | Illinois | United States | 41.85 | -87.67 | 830 | |
| Loxa | city | Illinois | United States | 39.50 | -88.27 | 830 | |
| Loyd | city | Illinois | United States | 39.91 | -89.85 | 830 |