Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| The Uncommons Shopping Center | Locale | 242 | Allen | 41 06 05 N | 085 09 45 W |
| The Village School | School | 254 | Huntington | 40 57 36 N | 085 30 40 W |
| The Way College of Biblical Research | Hospital | 287 | Noble | 41 30 17 N | 085 22 20 W |
| The Way of Holiness Church | Church | 201 | Porter | 41 32 12 N | 087 08 23 W |
| The Wesleyan Church | Church | 278 | DeKalb | 41 31 24 N | 084 54 10 W |
| The Wolf Den Airport | Airport | 247 | Huntington | 40 57 06 N | 085 23 17 W |
| Theis Creek | Stream | | Perry | 38 03 53 N | 086 44 38 W |
| Theis Ridge | Ridge | 180 | Perry | 38 03 40 N | 086 42 28 W |
| Theis School | School | 128 | Perry | 38 04 23 N | 086 42 22 W |
| Theodore Potter Elementary School | School | 224 | Marion | 39 46 51 N | 086 07 54 W |
| Theodore Roosevelt Branch Gary Public Library (historical) | Building | 184 | Lake | 41 34 25 N | 087 20 36 W |
| Theodore Roosevelt High School | School | 184 | Lake | 41 34 29 N | 087 20 42 W |
| Thiele Ditch | Canal | 240 | Allen | 40 57 03 N | 085 09 16 W |
| Thin Run | Stream | | Randolph | 40 02 55 N | 084 58 07 W |
| Third Avenue School | School | 115 | Posey | 37 59 30 N | 087 34 42 W |
| Third Basin | Lake | 299 | Steuben | 41 41 03 N | 085 04 20 W |
| Third Street Elementary School | School | 169 | Scott | 38 41 09 N | 085 46 01 W |
| Thomas | Populated Place | 136 | Daviess | 38 36 46 N | 087 13 54 W |
| Thomas A Edison Elementary School | School | 184 | Lake | 41 35 09 N | 087 30 37 W |
| Thomas A Edison Junior - Senior High School | School | 184 | Lake | 41 34 38 N | 087 14 40 W |
| Thomas A Edison Junior High School | School | 180 | Lake | 41 36 12 N | 087 24 17 W |
| Thomas A Edison Junior High School | School | 208 | Marion | 39 45 20 N | 086 10 52 W |
| Thomas A Edison Middle School | School | 228 | St. Joseph | 41 41 21 N | 086 12 36 W |
| Thomas A Hendricks Elementary School | School | 234 | Shelby | 39 31 14 N | 085 47 02 W |
| Thomas Branch | Stream | | Clark | 38 28 44 N | 085 51 12 W |
| Thomas Carr Howe High School | School | 241 | Marion | 39 46 05 N | 086 05 10 W |
| Thomas Cemetery | Cemetery | 241 | Parke | 39 45 29 N | 087 01 48 W |
| Thomas Cemetery | Cemetery | 295 | Rush | 39 30 17 N | 085 27 47 W |
| Thomas Cemetery | Cemetery | 168 | Vermillion | 39 53 43 N | 087 26 24 W |
| Thomas D Gregg Elementary School | School | 231 | Marion | 39 46 29 N | 086 07 20 W |
| Thomas Ditch | Canal | 270 | Jay | 40 31 01 N | 085 07 15 W |
| Thomas Ditch | Canal | 268 | Jay | 40 28 48 N | 085 06 55 W |
| Thomas J Miller Lake | Reservoir | 178 | Scott | 38 38 54 N | 085 43 24 W |
| Thomas J Miller Lake Dam | Dam | 178 | Scott | 38 38 54 N | 085 43 24 W |
| Thomas Jefferson Elementary School | School | 150 | Clark | 38 18 24 N | 085 44 40 W |
| Thomas Jefferson Elementary School | School | 256 | Grant | 40 32 17 N | 085 39 13 W |
| Thomas Jefferson Elementary School | School | 185 | Lake | 41 35 15 N | 087 29 10 W |
| Thomas Jefferson Elementary School | School | 246 | Porter | 41 29 03 N | 087 02 44 W |
| Thomas Jefferson Elementary School | School | 216 | St. Joseph | 41 40 14 N | 086 14 04 W |
| Thomas Jefferson Middle School | School | 247 | Porter | 41 28 59 N | 087 02 45 W |
| Thomas Lake | Lake | 238 | Marshall | 41 17 34 N | 086 23 41 W |
| Thomas Lake | Lake | 219 | Putnam | 39 36 48 N | 087 06 42 W |
| Thomas Lake | Reservoir | 209 | Greene | 38 55 42 N | 086 43 30 W |
| Thomas Lake | Reservoir | 184 | Owen | 39 15 30 N | 086 50 48 W |
| Thomas Lake | Reservoir | 237 | Putnam | 39 36 48 N | 086 59 54 W |
| Thomas Lake Dam | Dam | 209 | Greene | 38 55 42 N | 086 43 30 W |
| Thomas Lake Dam | Dam | 184 | Owen | 39 15 30 N | 086 50 48 W |
| Thomas Marshall Elementary School | School | 235 | Wabash | 41 00 19 N | 085 45 45 W |
| Thomas Park | Park | 261 | DeKalb | 41 22 18 N | 085 03 13 W |
| Thomas Park | Park | 294 | Delaware | 40 10 37 N | 085 24 32 W |
| Thomas School (historical) | School | 198 | Porter | 41 36 37 N | 087 03 15 W |
| Thomas Street Park | Park | 214 | Lake | 41 25 31 N | 087 21 19 W |
| Thomason Cemetery | Cemetery | 199 | Lawrence | 38 46 35 N | 086 30 56 W |
| Thomaston | Populated Place | 207 | LaPorte | 41 22 42 N | 086 48 51 W |
| Thomds Centennial Park | Park | 197 | Porter | 41 36 40 N | 087 03 09 W |
| Thompkins Elementary and Junior High School | School | 122 | Vanderburgh | 38 01 17 N | 087 34 56 W |
| Thompson Branch | Stream | | Jefferson | 38 45 17 N | 085 32 10 W |
| Thompson Branch | Stream | | Pulaski | 41 05 30 N | 086 43 25 W |
| Thompson Cemetery | Cemetery | 191 | Bartholomew | 39 11 13 N | 085 53 40 W |
| Thompson Cemetery | Cemetery | 219 | Cass | 40 52 05 N | 086 33 45 W |
| Thompson Cemetery | Cemetery | 271 | Delaware | 40 18 38 N | 085 31 29 W |
| Thompson Cemetery | Cemetery | 259 | Huntington | 40 42 31 N | 085 21 11 W |
| Thompson Cemetery | Cemetery | 203 | Jackson | 39 00 16 N | 086 12 03 W |
| Thompson Cemetery | Cemetery | 225 | Montgomery | 40 02 22 N | 086 59 53 W |
| Thompson Cemetery | Cemetery | 215 | Morgan | 39 26 55 N | 086 17 25 W |
| Thompson Cemetery | Cemetery | 180 | Washington | 38 45 11 N | 086 12 47 W |
| Thompson Chapel | Church | 195 | Harrison | 38 16 59 N | 086 15 23 W |
| Thompson Creek | Stream | | Floyd | 38 23 21 N | 085 55 30 W |
| Thompson Creek | Stream | | Hendricks | 39 46 44 N | 086 31 12 W |
| Thompson Ditch | Canal | 146 | Daviess | 38 46 47 N | 087 02 56 W |
| Thompson Ditch | Canal | 118 | Gibson | 38 17 14 N | 087 47 07 W |
| Thompson Ditch | Canal | 121 | Gibson | 38 19 36 N | 087 41 29 W |
| Thompson Ditch | Canal | 265 | Grant | 40 32 22 N | 085 29 54 W |
| Thompson Ditch | Canal | 253 | Hancock | 39 43 20 N | 085 50 51 W |
| Thompson Ditch | Canal | 209 | Jasper | 41 02 07 N | 087 15 07 W |
| Thompson Ditch | Canal | 122 | Knox | 38 27 35 N | 087 36 36 W |
| Thompson Ditch | Canal | 231 | Marion | 39 44 28 N | 086 18 16 W |
| Thompson Ditch | Canal | 221 | Marshall | 41 10 11 N | 086 26 35 W |
| Thompson Ditch | Canal | 197 | Newton | 40 51 27 N | 087 27 05 W |
| Thompson Ditch | Canal | 214 | Pulaski | 41 03 27 N | 086 34 09 W |
| Thompson Ditch | Canal | 210 | Pulaski | 41 05 25 N | 086 44 10 W |
| Thompson Ditch | Canal | 222 | Shelby | 39 27 01 N | 085 46 51 W |
| Thompson Ditch | Canal | 149 | Vigo | 39 25 03 N | 087 24 10 W |
| Thompson Lake | Reservoir | 272 | Bartholomew | 39 13 06 N | 086 03 54 W |
| Thompson Lake | Reservoir | 171 | Vigo | 39 26 40 N | 087 20 58 W |
| Thompson Lake Dam | Dam | 272 | Bartholomew | 39 13 06 N | 086 03 54 W |
| Thompson Mound | Summit | 107 | Posey | 38 02 09 N | 088 00 47 W |
| Thompson Road Independent Baptist Church | Church | 229 | Marion | 39 41 38 N | 086 07 45 W |
| Thompson Run | Stream | | Marion | 39 41 33 N | 086 13 20 W |
| Thompson School | School | 134 | Posey | 37 57 53 N | 087 51 55 W |
| Thompson School | School | 149 | Vigo | 39 27 55 N | 087 23 58 W |
| Thompson Slough | Stream | | Jackson | 38 59 56 N | 085 53 30 W |
| Thompsons Lake | Reservoir | 189 | Bartholomew | 39 06 47 N | 085 54 13 W |
| Thong Run | Stream | | Jay | 40 23 29 N | 085 11 57 W |
| Thor Run | Stream | | Hamilton | 39 56 55 N | 085 54 15 W |
| Thorn Cemetery | Cemetery | 286 | Noble | 41 18 11 N | 085 32 30 W |
| Thorn Creek | Stream | | Whitley | 41 12 23 N | 085 25 45 W |
| Thorn Creek Church | Church | 286 | Whitley | 41 11 59 N | 085 31 15 W |
| Thorn Creek Church | Church | 264 | Whitley | 41 12 02 N | 085 27 47 W |
| Thorn Ridge | Ridge | 257 | Switzerland | 38 42 45 N | 085 08 13 W |
| Thorn Run | Stream | | Posey | 38 05 34 N | 087 56 01 W |
| Thornburg Cemetery | Cemetery | 142 | Warrick | 38 01 59 N | 087 15 21 W |
| Thorncreek Center School | School | 276 | Whitley | 41 13 15 N | 085 28 60 W |
| Thornhope | Populated Place | 221 | Pulaski | 40 55 33 N | 086 31 46 W |
| Thornton | Populated Place | 155 | Lawrence | 38 55 00 N | 086 30 05 W |
| Thornton Cemetery | Cemetery | 192 | Jefferson | 38 52 47 N | 085 15 07 W |
| Thornton Park | Park | 207 | Lawrence | 38 51 36 N | 086 29 46 W |
| Thornton School | School | 150 | Vigo | 39 27 20 N | 087 22 22 W |
| Thorntown | Populated Place | 261 | Boone | 40 07 46 N | 086 36 24 W |
| Thorpe Creek | Stream | | Madison | 39 57 14 N | 085 54 32 W |