Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Troutman Grove Cemetery | Cemetery | 182 | Will | 41 27 10 N | 088 07 40 W |
| Troutman Grove School (historical) | School | 185 | Will | 41 27 05 N | 088 07 04 W |
| Trovero Airport | Airport | 193 | La Salle | 41 17 55 N | 089 06 33 W |
| Trowbridge | Populated Place | 197 | Shelby | 39 18 37 N | 088 31 04 W |
| Troxel | Populated Place | 241 | Kane | 41 50 03 N | 088 35 47 W |
| Troy | Populated Place | 171 | Madison | 38 43 45 N | 089 52 59 W |
| Troy (historical) | Populated Place | 173 | Fulton | 40 41 27 N | 090 20 06 W |
| Troy Assembly of God Church | Church | 154 | Madison | 38 39 16 N | 089 52 44 W |
| Troy Baptist Church | Church | 171 | Madison | 38 43 40 N | 089 53 00 W |
| Troy Bethel Baptist Church | Church | 167 | Madison | 38 43 54 N | 089 52 50 W |
| Troy Christian Church | Church | 171 | Madison | 38 43 47 N | 089 52 59 W |
| Troy Church of Christ | Church | 173 | Madison | 38 42 59 N | 089 54 54 W |
| Troy City Cemetery | Cemetery | 167 | Madison | 38 43 31 N | 089 53 03 W |
| Troy City Hall | Building | 169 | Madison | 38 43 45 N | 089 52 55 W |
| Troy City Park | Park | 171 | Madison | 38 43 45 N | 089 53 33 W |
| Troy Craughwell School | School | 185 | Will | 41 32 14 N | 088 09 51 W |
| Troy Crossing | Populated Place | 171 | Madison | 38 42 20 N | 089 57 25 W |
| Troy Grove | Populated Place | 205 | La Salle | 41 28 04 N | 089 04 59 W |
| Troy Grove Stone Quarry | Mine | 162 | La Salle | 41 27 58 N | 089 04 24 W |
| Troy Heritage Trail Elementary School | School | 182 | Will | 41 30 22 N | 088 09 52 W |
| Troy Junction | Populated Place | 175 | Madison | 38 44 04 N | 089 55 41 W |
| Troy Junior High School | School | 186 | Will | 41 32 07 N | 088 11 43 W |
| Troy Post Office | Post Office | 171 | Madison | 38 43 48 N | 089 53 00 W |
| Troy Presbyterian Church | Church | 170 | Madison | 38 43 34 N | 089 53 01 W |
| Troy School | School | 167 | Madison | 38 43 49 N | 089 52 51 W |
| Troy School (historical) | School | 205 | Fulton | 40 40 45 N | 090 20 15 W |
| Troy School (historical) | School | 152 | Richland | 38 43 01 N | 088 02 36 W |
| Troy United Methodist Church | Church | 170 | Madison | 38 43 57 N | 089 53 24 W |
| Troy United Pentecostal Church | Church | 170 | Madison | 38 43 45 N | 089 52 57 W |
| Troy-Shorewood School | School | 176 | Will | 41 31 05 N | 088 11 44 W |
| Troyer Cemetery | Cemetery | 255 | McLean | 40 35 24 N | 089 04 52 W |
| Truax Lake | Reservoir | 198 | Fulton | 40 31 54 N | 090 09 12 W |
| Truax Lake Dam | Dam | 198 | Fulton | 40 31 54 N | 090 09 12 W |
| True Believers Missionary Baptist Church | Church | 185 | Cook | 41 45 06 N | 087 40 13 W |
| True Church House of Prayer to all Nations | Church | 182 | Cook | 41 46 18 N | 087 39 12 W |
| True Church of Christ Devine | Church | 184 | Cook | 41 45 46 N | 087 39 50 W |
| True Church of Holiness | Church | 184 | Cook | 41 45 06 N | 087 39 49 W |
| True Faith Missionary Baptist Church | Church | 185 | Cook | 41 53 40 N | 087 44 53 W |
| True Foundation Missionary Baptist Church | Church | 182 | Cook | 41 45 13 N | 087 38 40 W |
| True Gospel Missionary Baptist Church | Church | 189 | Cook | 41 53 55 N | 087 46 20 W |
| True Holiness Church of God | Church | 184 | Cook | 41 36 42 N | 087 39 05 W |
| True Light Baptist Church | Church | 200 | Cook | 41 30 13 N | 087 35 43 W |
| True Light Baptist Church | Church | 124 | St. Clair | 38 36 31 N | 090 09 23 W |
| True Light Church | Church | 104 | Pulaski | 37 10 36 N | 089 14 13 W |
| True Macedonia Missionary Baptist Church | Church | 185 | Cook | 41 53 40 N | 087 44 56 W |
| True Reformed Church | Church | 183 | Cook | 41 36 04 N | 087 36 29 W |
| True Tabernacle | Church | 182 | Cook | 41 51 04 N | 087 43 32 W |
| True Tabernacle Church of God | Church | 182 | Cook | 41 51 02 N | 087 43 30 W |
| True Temple Church of God in Christ | Church | 183 | Cook | 41 46 28 N | 087 39 51 W |
| True Vine Baptist Church (historical) | Church | 173 | Bond | 38 53 13 N | 089 24 38 W |
| True Vine Church of God in Christ | Church | 183 | Cook | 41 51 57 N | 087 43 24 W |
| True Vine Missionary Baptist Church | Church | 183 | Cook | 41 46 18 N | 087 38 07 W |
| True Way Presbyterian Church (historical) | Church | 183 | Cook | 42 01 08 N | 087 43 41 W |
| True-Way Apostolic Faith Church | Church | 181 | Cook | 41 46 50 N | 087 36 50 W |
| Truelove School (historical) | School | 160 | Union | 37 31 02 N | 089 05 51 W |
| Truevine Baptist Church | Church | 189 | Cook | 41 53 42 N | 087 46 28 W |
| Trulock Lake | Reservoir | 190 | Christian | 39 25 46 N | 089 26 44 W |
| Truman College | School | 182 | Cook | 41 57 53 N | 087 39 33 W |
| Trumbo Cemetery | Cemetery | 187 | La Salle | 41 23 24 N | 088 45 34 W |
| Trumbull Elementary School | School | 183 | Cook | 41 58 35 N | 087 40 13 W |
| Trumbull Oil Field | Oilfield | 123 | White | 38 04 17 N | 088 16 46 W |
| Trumbull Park | Park | 179 | Cook | 41 42 23 N | 087 33 51 W |
| Trumbull Park Homes (subdivision) | Populated Place | 179 | Cook | 41 42 09 N | 087 33 52 W |
| Trumbull Park Terrace (subdivision) | Populated Place | 178 | Cook | 41 42 34 N | 087 33 43 W |
| Truro | Populated Place | 208 | Knox | 40 57 27 N | 090 02 32 W |
| Trustees System Service Building | Building | 182 | Cook | 41 53 10 N | 087 38 01 W |
| Truth Bethesda Missionary Baptist Church | Church | 184 | Cook | 41 45 06 N | 087 39 50 W |
| Truth-Child Parent Center | School | 180 | Cook | 41 54 26 N | 087 38 44 W |
| Tryons Grove School (historical) | School | 280 | McHenry | 42 25 23 N | 088 22 28 W |
| Tubbs School (historical) | School | 214 | Warren | 40 50 59 N | 090 43 50 W |
| Tucker Cemetery | Cemetery | 183 | Brown | 39 54 17 N | 090 47 37 W |
| Tucker Ditch | Canal | 104 | Massac | 37 16 00 N | 088 51 42 W |
| Tucker Hill | Summit | 195 | Hardin | 37 32 51 N | 088 09 01 W |
| Tucker Hollow | Valley | | Knox | 40 56 23 N | 090 00 01 W |
| Tucker Knob | Summit | 270 | Jersey | 38 58 55 N | 090 30 28 W |
| Tucker School (historical) | School | 107 | Massac | 37 14 08 N | 088 49 15 W |
| Tucker School (historical) | School | 201 | Peoria | 40 48 48 N | 089 43 32 W |
| Tucker School (historical) | School | 190 | Sangamon | 39 34 26 N | 089 41 22 W |
| Tucker School (historical) | School | 217 | Woodford | 40 42 01 N | 089 00 16 W |
| Tuckers Corners | Populated Place | 134 | Hamilton | 37 59 27 N | 088 35 44 W |
| Tuley Park | Park | 179 | Cook | 41 43 49 N | 087 36 41 W |
| Tull Cemetery | Cemetery | 204 | Hancock | 40 36 59 N | 091 14 30 W |
| Tull School (historical) | School | 210 | Hancock | 40 36 33 N | 091 14 47 W |
| Tullamore School (historical) | School | 172 | Tazewell | 40 26 03 N | 089 30 03 W |
| Tulley School (historical) | School | 143 | Williamson | 37 45 20 N | 088 50 09 W |
| Tullis School (historical) | School | 205 | Schuyler | 40 08 47 N | 090 35 06 W |
| Tully Island | Island | 147 | Adams | 40 10 52 N | 091 30 26 W |
| Tully Park | Park | 165 | Marion | 38 37 55 N | 088 56 14 W |
| Tuma Lake | Lake | 204 | Cook | 41 42 21 N | 087 52 17 W |
| Tunbridge | Populated Place | 195 | De Witt | 40 06 49 N | 089 02 55 W |
| Tunbridge Cemetery | Cemetery | 214 | De Witt | 40 06 35 N | 089 03 02 W |
| Tunison Park | Park | 170 | Greene | 39 26 01 N | 090 23 43 W |
| Tunnel Hill | Populated Place | 194 | Johnson | 37 31 25 N | 088 50 19 W |
| Tunnel Hill Center | School | 230 | Johnson | 37 30 49 N | 088 49 54 W |
| Tunnel Hill Election Precinct | Civil | 206 | Johnson | 37 32 44 N | 088 52 41 W |
| Tunnel Hill Post Office | Post Office | 192 | Johnson | 37 31 27 N | 088 50 17 W |
| Tunnel Hill School | School | 188 | Union | 37 30 03 N | 089 17 51 W |
| Tunnison Cemetery | Cemetery | 194 | Greene | 39 29 50 N | 090 20 24 W |
| Tunnison Creek | Stream | | Winnebago | 42 23 34 N | 089 13 55 W |
| Tureman Cemetery | Cemetery | 179 | Cass | 39 56 48 N | 090 16 36 W |
| Turkey Bayou | Lake | 104 | Jackson | 37 41 07 N | 089 24 52 W |
| Turkey Bayou Campground | Locale | 104 | Jackson | 37 40 59 N | 089 24 45 W |
| Turkey Bend School (historical) | School | 148 | Washington | 38 13 44 N | 089 17 12 W |
| Turkey Branch | Stream | | Fulton | 40 17 33 N | 090 11 53 W |
| Turkey Chute | Gut | 155 | Henderson | 40 41 06 N | 091 06 06 W |
| Turkey Creek | Stream | | Cumberland | 39 12 08 N | 088 20 50 W |
| Turkey Creek | Stream | | Fulton | 40 31 53 N | 090 16 42 W |
| Turkey Creek | Stream | | Gallatin | 37 38 10 N | 088 13 56 W |
| Turkey Creek | Stream | | Greene | 39 29 49 N | 090 14 27 W |
| Turkey Creek | Stream | | Jasper | 39 02 07 N | 088 11 32 W |