Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Trinity Lutheran Church | Church | 218 | McLean | 40 44 36 N | 088 43 11 W |
| Trinity Lutheran Church | Church | 181 | Morgan | 39 50 10 N | 090 27 55 W |
| Trinity Lutheran Church | Church | 285 | Ogle | 42 02 44 N | 089 25 42 W |
| Trinity Lutheran Church | Church | 184 | Peoria | 40 42 04 N | 089 35 53 W |
| Trinity Lutheran Church | Church | 165 | Richland | 38 43 57 N | 088 03 01 W |
| Trinity Lutheran Church | Church | 221 | Rock Island | 41 25 17 N | 090 27 58 W |
| Trinity Lutheran Church | Church | 192 | Sangamon | 39 35 19 N | 089 45 19 W |
| Trinity Lutheran Church | Church | 196 | Shelby | 39 15 47 N | 088 37 29 W |
| Trinity Lutheran Church | Church | 128 | St. Clair | 38 37 49 N | 090 06 22 W |
| Trinity Lutheran Church | Church | 198 | Union | 37 27 35 N | 089 15 06 W |
| Trinity Lutheran Church | Church | 181 | Vermilion | 40 07 31 N | 087 36 48 W |
| Trinity Lutheran Church | Church | 160 | Washington | 38 26 40 N | 089 16 29 W |
| Trinity Lutheran Church | Church | 221 | Will | 41 26 34 N | 087 37 44 W |
| Trinity Lutheran Church | Church | 194 | Will | 41 31 02 N | 087 57 56 W |
| Trinity Lutheran Church | Church | 124 | Williamson | 37 48 45 N | 089 01 38 W |
| Trinity Lutheran Church | Church | 225 | Winnebago | 42 16 11 N | 089 05 17 W |
| Trinity Lutheran Church | Church | 228 | Woodford | 40 44 30 N | 089 01 26 W |
| Trinity Lutheran Church | Church | 228 | Woodford | 40 48 01 N | 089 11 53 W |
| Trinity Lutheran Church (historical) | Church | 150 | Richland | 38 43 44 N | 088 04 48 W |
| Trinity Lutheran School | School | 199 | Cook | 41 44 18 N | 087 54 14 W |
| Trinity Lutheran School | School | 231 | DuPage | 41 52 46 N | 088 12 40 W |
| Trinity Lutheran School | School | 228 | DuPage | 41 58 32 N | 088 04 23 W |
| Trinity Lutheran School | School | 162 | Madison | 38 49 00 N | 089 57 07 W |
| Trinity Lutheran School | School | 173 | Madison | 38 55 46 N | 089 50 27 W |
| Trinity Lutheran School | School | 248 | McLean | 40 28 21 N | 088 59 45 W |
| Trinity Lutheran School | School | 195 | Shelby | 39 15 47 N | 088 37 27 W |
| Trinity Lutheran School | School | 160 | Washington | 38 26 38 N | 089 16 29 W |
| Trinity Memorial Cemetery | Cemetery | 250 | Ogle | 41 56 57 N | 089 03 37 W |
| Trinity Mennonite Church | Church | 210 | Tazewell | 40 35 25 N | 089 27 35 W |
| Trinity Methodist Church | Church | 216 | McDonough | 40 27 58 N | 090 39 26 W |
| Trinity Methodist Episcopal Church (historical) | Church | 204 | Macon | 39 50 40 N | 088 57 07 W |
| Trinity Presbyterian Church | Church | 193 | Cook | 41 41 34 N | 087 40 19 W |
| Trinity Presbyterian Church | Church | 199 | Cook | 41 55 43 N | 087 54 16 W |
| Trinity Presbyterian Church | Church | 109 | Massac | 37 09 06 N | 088 43 47 W |
| Trinity Presbyterian Church | Church | 225 | Mercer | 41 11 58 N | 090 45 03 W |
| Trinity Presbyterian Church | Church | 196 | Peoria | 40 38 12 N | 089 40 47 W |
| Trinity School | School | 139 | Clinton | 38 32 53 N | 089 15 50 W |
| Trinity School | School | 192 | Cook | 41 33 56 N | 087 33 23 W |
| Trinity School | School | 223 | Cook | 41 36 10 N | 087 47 09 W |
| Trinity School | School | 182 | Cook | 41 50 17 N | 087 38 35 W |
| Trinity School | School | 216 | DuPage | 41 51 41 N | 087 59 31 W |
| Trinity School | School | 154 | Marion | 38 31 28 N | 089 06 56 W |
| Trinity School | School | 125 | Randolph | 38 11 02 N | 089 56 37 W |
| Trinity School | School | 182 | Sangamon | 39 47 50 N | 089 40 07 W |
| Trinity School | School | 181 | Vermilion | 40 07 32 N | 087 36 46 W |
| Trinity School | School | 152 | Washington | 38 20 43 N | 089 23 21 W |
| Trinity School | School | 221 | Will | 41 26 35 N | 087 37 45 W |
| Trinity School | School | 185 | Will | 41 31 40 N | 088 00 17 W |
| Trinity School (historical) | School | 232 | DuPage | 41 58 23 N | 088 04 04 W |
| Trinity School (historical) | School | 153 | Marion | 38 34 56 N | 088 45 48 W |
| Trinity Slovak Lutheran Church | Church | 186 | Cook | 41 58 28 N | 087 44 58 W |
| Trinity Tabernacle Baptist Church | Church | 181 | Cook | 41 48 44 N | 087 37 59 W |
| Trinity Temple Church | Church | 155 | Peoria | 40 42 05 N | 089 35 05 W |
| Trinity United Church of Christ | Church | 179 | Adams | 39 54 25 N | 091 22 43 W |
| Trinity United Church of Christ | Church | 182 | Cook | 41 43 18 N | 087 38 16 W |
| Trinity United Church of Christ | Church | 169 | La Salle | 41 19 55 N | 089 05 37 W |
| Trinity United Church of Christ | Church | 203 | Lake | 42 10 56 N | 087 50 48 W |
| Trinity United Church of Christ | Church | 201 | Vermilion | 40 02 54 N | 087 38 10 W |
| Trinity United Church of Christ Cemetery | Cemetery | 127 | St. Clair | 38 22 19 N | 089 47 54 W |
| Trinity United Methodist Church | Church | 193 | Clark | 39 23 13 N | 087 41 36 W |
| Trinity United Methodist Church | Church | 149 | Clay | 38 40 11 N | 088 29 30 W |
| Trinity United Methodist Church | Church | 188 | Cook | 41 52 01 N | 087 46 26 W |
| Trinity United Methodist Church | Church | 203 | Cook | 42 02 48 N | 087 56 47 W |
| Trinity United Methodist Church | Church | 186 | Cook | 42 04 45 N | 087 42 14 W |
| Trinity United Methodist Church | Church | 214 | Edgar | 39 37 11 N | 087 41 46 W |
| Trinity United Methodist Church | Church | 146 | Franklin | 37 54 02 N | 088 54 13 W |
| Trinity United Methodist Church | Church | 267 | Kane | 42 06 42 N | 088 15 34 W |
| Trinity United Methodist Church | Church | 186 | Kankakee | 41 06 37 N | 087 52 15 W |
| Trinity United Methodist Church | Church | 128 | Madison | 38 42 21 N | 090 07 38 W |
| Trinity United Methodist Church | Church | 169 | Marion | 38 38 06 N | 088 57 19 W |
| Trinity United Methodist Church | Church | 135 | Wabash | 38 24 42 N | 087 45 38 W |
| Trinity United Methodist Church | Church | 206 | Whiteside | 41 47 42 N | 089 41 42 W |
| Trinity United Methodist Church | Church | 196 | Will | 41 31 53 N | 088 02 58 W |
| Trinity United Presbyterian Church | Church | 163 | Randolph | 38 07 21 N | 089 42 21 W |
| Trinity Vineyard Christian Church | Church | 223 | Kane | 41 54 52 N | 088 18 22 W |
| Triopia Junior-Senior High School | School | 178 | Morgan | 39 50 27 N | 090 22 18 W |
| Triple Creek Airport | Airport | 203 | Piatt | 39 53 47 N | 088 31 20 W |
| Triple Lakes | Lake | 169 | St. Clair | 38 31 05 N | 090 10 19 W |
| Triplett Cemetery | Cemetery | 197 | Bureau | 41 21 20 N | 089 32 22 W |
| Tripp Cemetery | Cemetery | 219 | La Salle | 41 35 21 N | 088 59 44 W |
| Tripp Cemetery | Cemetery | 195 | Pike | 39 35 24 N | 090 43 58 W |
| Tripp Primary Learning Center | School | 184 | Cook | 42 01 42 N | 087 44 02 W |
| Tripp School (historical) | School | 196 | Lake | 42 10 24 N | 087 55 23 W |
| Tripp School (historical) | School | 124 | Union | 37 28 04 N | 089 18 11 W |
| Triton College | School | 192 | Cook | 41 54 54 N | 087 50 33 W |
| Triumph | Populated Place | 204 | La Salle | 41 29 58 N | 089 01 19 W |
| Triumph Post Office | Post Office | 204 | La Salle | 41 29 58 N | 089 01 20 W |
| Triumph School (historical) | School | 234 | Ogle | 42 07 46 N | 089 22 32 W |
| Trivoli | Populated Place | 229 | Peoria | 40 41 26 N | 089 53 31 W |
| Trivoli Cemetery | Cemetery | 225 | Peoria | 40 41 48 N | 089 54 20 W |
| Trivoli Fire Station | Building | 227 | Peoria | 40 41 53 N | 089 53 39 W |
| Trivoli Post Office | Post Office | 228 | Peoria | 40 41 27 N | 089 53 59 W |
| Trobaugh Cemetery | Cemetery | 150 | Richland | 38 47 43 N | 088 07 37 W |
| Troster | Populated Place | 224 | McLean | 40 19 06 N | 088 28 47 W |
| Trotter Cemetery | Cemetery | 132 | Wayne | 38 16 21 N | 088 32 43 W |
| Trotter School (historical) | School | 130 | Wayne | 38 16 13 N | 088 32 18 W |
| Troublemakers Park | Park | 186 | Cook | 41 40 08 N | 087 40 09 W |
| Troublesome Creek | Stream | | McDonough | 40 19 41 N | 090 51 59 W |
| Troup Quarry | Mine | 164 | La Salle | 41 30 42 N | 088 41 50 W |
| Trousdale School (historical) | School | 133 | White | 38 04 48 N | 088 19 07 W |
| Trout Family Cemetery | Cemetery | 122 | Saline | 37 44 25 N | 088 38 19 W |
| Trout Hollow | Valley | | Monroe | 38 19 54 N | 090 16 07 W |
| Trout Park | Park | 244 | Kane | 42 03 54 N | 088 16 00 W |
| Trout Park Nature Preserve | Park | 229 | Kane | 42 03 55 N | 088 16 06 W |
| Trout Pond | Reservoir | 147 | Wayne | 38 32 11 N | 088 34 29 W |
| Trout School (historical) | School | 191 | La Salle | 41 14 39 N | 089 02 06 W |
| Trout School (historical) | School | 153 | Mason | 40 17 48 N | 089 54 30 W |
| Trout Valley | Populated Place | 242 | McHenry | 42 11 53 N | 088 15 12 W |
| Trout Valley Park | Park | 225 | McHenry | 42 11 33 N | 088 15 07 W |
| Troutman Cemetery | Cemetery | 153 | Hardin | 37 26 23 N | 088 22 39 W |