Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Twin City Nazarene School | School | 205 | Whiteside | 41 47 39 N | 089 40 46 W |
| Twin Echo Elementary School | School | 144 | Madison | 38 39 01 N | 089 59 46 W |
| Twin Grove Junior High School | School | 218 | Lake | 42 10 03 N | 087 58 54 W |
| Twinbrook Elementary School | School | 231 | Cook | 42 02 47 N | 088 04 08 W |
| Twiss Hill School (historical) | School | 169 | St. Clair | 38 33 12 N | 090 04 47 W |
| Twomile School (historical) | School | 198 | Moultrie | 39 37 34 N | 088 33 58 W |
| Tygett School (historical) | School | 171 | Union | 37 31 52 N | 089 09 52 W |
| Tyler Elementary School | School | 258 | DeKalb | 41 55 11 N | 088 45 57 W |
| Tyler School (historical) | School | 190 | Will | 41 38 18 N | 088 09 43 W |
| Tylerville School (historical) | School | 221 | Warren | 40 59 18 N | 090 29 48 W |
| Tyng Primary School | School | 163 | Peoria | 40 40 45 N | 089 37 42 W |
| Tyrell School (historical) | School | 273 | Kane | 42 05 34 N | 088 21 33 W |
| U S Grant Middle School | School | 180 | Sangamon | 39 47 57 N | 089 41 00 W |
| Ullrich School | School | 206 | Macon | 39 51 08 N | 088 57 00 W |
| Union Brick School | School | 192 | Montgomery | 39 15 40 N | 089 28 54 W |
| Union Center School (historical) | School | 223 | Champaign | 40 17 48 N | 088 12 49 W |
| Union Center School (historical) | School | 193 | Fulton | 40 19 10 N | 090 23 30 W |
| Union Central School (historical) | School | 207 | Douglas | 39 39 09 N | 088 18 09 W |
| Union Douglas Elementary School | School | 202 | Hancock | 40 24 37 N | 091 08 07 W |
| Union Elementary School | School | 194 | Will | 41 29 50 N | 088 01 27 W |
| Union Grove School | School | 158 | Madison | 38 49 08 N | 089 51 52 W |
| Union Grove School (historical) | School | 168 | Bond | 38 57 18 N | 089 25 44 W |
| Union Grove School (historical) | School | 177 | Cass | 39 53 00 N | 090 19 42 W |
| Union Grove School (historical) | School | 172 | Greene | 39 30 22 N | 090 10 05 W |
| Union Grove School (historical) | School | 137 | Jefferson | 38 14 05 N | 088 43 19 W |
| Union Grove School (historical) | School | 157 | Madison | 38 49 07 N | 089 51 50 W |
| Union Grove School (historical) | School | 186 | Morgan | 39 49 01 N | 090 08 45 W |
| Union Grove School (historical) | School | 200 | Schuyler | 40 16 14 N | 090 36 08 W |
| Union Grove School (historical) | School | 159 | Williamson | 37 47 24 N | 088 50 10 W |
| Union High School | School | 215 | Henderson | 40 50 59 N | 090 54 04 W |