Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Symerton | Populated Place | 195 | Will | 41 19 43 N | 088 03 09 W |
| Symmes Townhall | Building | 231 | Edgar | 39 32 52 N | 087 42 05 W |
| Synder Cemetery | Cemetery | 168 | Marion | 38 31 53 N | 088 59 05 W |
| Systran School | School | 180 | Cook | 41 53 25 N | 087 37 49 W |
| Szkola School | School | 181 | Cook | 41 48 35 N | 087 40 20 W |
| T E Culbertson Elementary School | School | 184 | Will | 41 31 23 N | 088 02 38 W |
| T H Mandy Shopping Center | Locale | 223 | DuPage | 41 50 09 N | 088 01 06 W |
| T Lake | Reservoir | 223 | Knox | 41 01 30 N | 090 02 33 W |
| Tabernacle Baptist Church | Church | 192 | Cook | 41 53 28 N | 087 50 34 W |
| Tabernacle Baptist Church | Church | 167 | Madison | 38 54 30 N | 090 08 54 W |
| Tabernacle Baptist Church | Church | 155 | Peoria | 40 41 16 N | 089 36 49 W |
| Tabernacle Christian Academy | School | 189 | Cook | 41 41 40 N | 087 39 11 W |
| Tabernacle Christian Church | Church | 201 | Whiteside | 41 47 57 N | 089 43 02 W |
| Tabernacle Church of God | Church | 183 | Cook | 41 51 44 N | 087 43 23 W |
| Tabernacle Church of God in Christ | Church | 236 | Winnebago | 42 15 44 N | 089 06 22 W |
| Tabernacle Church of Perfect Love | Church | 181 | Cook | 41 51 35 N | 087 42 31 W |
| Tabernacle Number One Gods Church of Holiness in Christ | Church | 187 | Cook | 41 41 44 N | 087 38 34 W |
| Tabernacle of Zion of the Apostolic Faith | Church | 186 | Cook | 41 41 08 N | 087 37 51 W |
| Table Grove | Populated Place | 221 | Fulton | 40 21 51 N | 090 25 30 W |
| Table Grove Community Church | Church | 223 | Fulton | 40 21 59 N | 090 25 31 W |
| Table Grove School (historical) | School | 218 | Fulton | 40 22 01 N | 090 25 50 W |
| Table Grove Village Square | Park | 223 | Fulton | 40 21 57 N | 090 25 30 W |
| Tabor | Populated Place | 204 | De Witt | 40 10 50 N | 089 08 05 W |
| Tabor Evangelical Lutheran Church | Church | 179 | Cook | 41 45 02 N | 087 33 15 W |
| Tabor Evangelical Lutheran Church | Church | 182 | Cook | 41 57 47 N | 087 43 02 W |
| Tabor Lutheran Church | Church | 182 | Cook | 41 47 50 N | 087 41 17 W |
| Tabor Lutheran Church | Church | 241 | Winnebago | 42 15 15 N | 089 03 37 W |
| Tabor United Church of Christ | Church | 187 | Cook | 41 57 16 N | 087 45 16 W |
| Tadlock Branch | Stream | | Marion | 38 38 20 N | 088 49 08 W |
| Tadpole School (historical) | School | 232 | Bureau | 41 15 49 N | 089 40 59 W |
| Tae Kwon-Do School | School | 179 | Cook | 41 43 51 N | 087 35 01 W |
| Taehyun Korean Presbyterian Church | Church | 183 | Cook | 41 56 47 N | 087 39 34 W |
| Taft Airport | Airport | 178 | Sangamon | 39 44 31 N | 089 28 42 W |
| Taft Elementary School | School | 202 | Will | 41 32 37 N | 088 07 01 W |
| Taft Grade School | School | 199 | Will | 41 34 52 N | 088 03 31 W |
| Taft Hall | Building | 227 | Champaign | 40 06 07 N | 088 14 01 W |
| Taft High School | School | 190 | Cook | 41 59 03 N | 087 47 33 W |
| Taft Park | Park | 183 | Cook | 41 35 47 N | 087 37 57 W |
| Taft Primary School | School | 189 | Kankakee | 41 06 38 N | 087 53 04 W |
| Taft School | School | 184 | Cook | 41 35 38 N | 087 37 57 W |
| Taft School (historical) | School | 207 | Warren | 40 38 37 N | 090 30 10 W |
| Taft School (historical) | School | 222 | Winnebago | 42 23 53 N | 089 02 23 W |
| Taggart Cemetery | Cemetery | 167 | Schuyler | 40 10 25 N | 090 42 59 W |
| Tait Bridge | Bridge | 112 | Edwards | 38 16 12 N | 088 08 16 W |
| Tait School (historical) | School | 257 | Winnebago | 42 19 52 N | 089 08 46 W |
| Taiwan Christian Church | Church | 200 | Cook | 42 01 26 N | 087 54 41 W |
| Taka School of Martial Arts | School | 179 | Cook | 41 45 32 N | 087 33 34 W |
| Talala Elementary School | School | 220 | Will | 41 28 10 N | 087 41 48 W |
| Talbot Cemetery | Cemetery | 238 | Henry | 41 17 37 N | 090 09 17 W |
| Talbot Cemetery | Cemetery | 131 | St. Clair | 38 21 28 N | 089 57 28 W |
| Talbot Creek | Stream | | Warren | 40 57 43 N | 090 37 30 W |
| Talbot Laboratory | Building | 219 | Champaign | 40 06 43 N | 088 13 42 W |
| Talbot School (historical) | School | 196 | Jackson | 37 49 14 N | 089 30 38 W |
| Talbot School (historical) | School | 244 | Knox | 41 05 33 N | 090 16 06 W |
| Talbott | Populated Place | 147 | Tazewell | 40 30 37 N | 089 47 04 W |
| Talbott Cemetery | Cemetery | 134 | Jackson | 37 47 09 N | 089 31 17 W |
| Talbott Hollow | Valley | | Jackson | 37 47 34 N | 089 32 59 W |
| Talbott Landing | Locale | 104 | Gallatin | 37 36 51 N | 088 09 00 W |
| Talbott School (historical) | School | 231 | Whiteside | 41 54 57 N | 089 38 54 W |
| Talcott Elementary School | School | 182 | Cook | 41 53 34 N | 087 40 26 W |
| Talcott Free Public Library | Building | 226 | Winnebago | 42 27 11 N | 089 04 19 W |
| Talcott Hall | Building | 247 | Winnebago | 42 16 17 N | 089 01 03 W |
| Talcott-Page Park | Park | 219 | Winnebago | 42 17 06 N | 089 06 17 W |
| Tall Oaks (subdivision) | Populated Place | 225 | Lake | 42 10 47 N | 088 02 20 W |
| Tall Oaks Country Club | Locale | 213 | Marshall | 40 56 24 N | 089 08 33 W |
| Tall Oaks Picnic Area | Locale | 180 | Kendall | 41 37 55 N | 088 32 03 W |
| Tall Timbers Lake East | Reservoir | 194 | Macoupin | 39 02 54 N | 089 45 48 W |
| Tall Timbers Lake East Dam | Dam | 194 | Macoupin | 39 02 54 N | 089 45 48 W |
| Tall Timbers Lake West | Reservoir | 191 | Macoupin | 39 03 00 N | 089 46 00 W |
| Tall Timbers Lake West Dam | Dam | 191 | Macoupin | 39 03 00 N | 089 46 00 W |
| Tall Tree Lake | Reservoir | 136 | Johnson | 37 28 30 N | 088 56 18 W |
| Tall Tree Lake Dam | Dam | 136 | Johnson | 37 28 30 N | 088 56 18 W |
| Tall Tree School (historical) | School | 204 | Johnson | 37 28 04 N | 088 55 33 W |
| Tall Trees (subdivision) | Populated Place | 259 | Lake | 42 09 21 N | 088 06 15 W |
| Tall Trees Park | Park | 191 | Cook | 42 04 50 N | 087 48 12 W |
| Talley Ferry (historical) | Crossing | 99 | Gallatin | 37 38 08 N | 088 13 47 W |
| Tallgrass Nature Trail | Trail | 157 | Grundy | 41 21 32 N | 088 18 40 W |
| Tallmadge | Populated Place | 193 | Kankakee | 41 06 41 N | 087 37 30 W |
| Tallmadge Park | Park | 186 | Cook | 42 03 35 N | 087 41 03 W |
| Tallula | Populated Place | 190 | Menard | 39 56 40 N | 089 56 14 W |
| Tallula Christian Church | Church | 189 | Menard | 39 56 53 N | 089 56 18 W |
| Tallula Elementary School | School | 189 | Menard | 39 56 50 N | 089 56 06 W |
| Tallula Freewill Baptist Church | Church | 189 | Menard | 39 56 51 N | 089 56 12 W |
| Tallula Number 11 Election Precinct | Civil | 182 | Menard | 39 56 56 N | 089 56 28 W |
| Taly Park | Park | 212 | Kane | 41 58 19 N | 088 17 35 W |
| Tam O'Shanter Country Club (historical) | Locale | 189 | Cook | 42 01 01 N | 087 47 41 W |
| Tamalco | Populated Place | 146 | Bond | 38 46 15 N | 089 17 29 W |
| Tamalco Access Area | Locale | 137 | Bond | 38 46 11 N | 089 15 25 W |
| Tamalco Post Office (historical) | Post Office | 144 | Bond | 38 46 16 N | 089 17 33 W |
| Tamara Heights | Populated Place | 283 | Kane | 42 00 10 N | 088 25 52 W |
| Tamarack | Populated Place | 207 | Will | 41 39 03 N | 088 15 10 W |
| Tamarack Country Club | Locale | 178 | St. Clair | 38 33 50 N | 089 54 40 W |
| Tamarack Fairways Golf Course | Locale | 202 | Will | 41 41 08 N | 088 12 42 W |
| Tamarack Park | Park | 212 | Cook | 42 02 46 N | 087 58 08 W |
| Tamarack School (historical) | School | 207 | Will | 41 39 01 N | 088 15 04 W |
| Tamarack View Trail | Trail | 231 | Lake | 42 21 10 N | 088 10 52 W |
| Tamarawa Ridge | Ridge | 135 | Monroe | 38 18 12 N | 089 55 34 W |
| Tamaroa | Populated Place | 155 | Perry | 38 08 16 N | 089 13 48 W |
| Tamaroa Cemetery | Cemetery | 153 | Perry | 38 08 47 N | 089 13 30 W |
| Tamaroa Elementary School | School | 156 | Perry | 38 08 18 N | 089 13 54 W |
| Tamaroa Number 1 Election Precinct | Civil | 147 | Perry | 38 08 10 N | 089 10 53 W |
| Tamaroa Number 2 Election Precinct | Civil | 156 | Perry | 38 09 02 N | 089 15 19 W |
| Tamaroa Oil Field | Oilfield | 145 | Perry | 38 10 10 N | 089 10 38 W |
| Tamaroa South Oil Field | Oilfield | 142 | Perry | 38 06 55 N | 089 12 38 W |
| Tamera Heights Park | Park | 210 | DuPage | 41 56 45 N | 087 59 57 W |
| Tammany School (historical) | School | 260 | Stephenson | 42 23 46 N | 089 33 58 W |
| Tammora Cemetery | Cemetery | 150 | St. Clair | 38 18 42 N | 089 54 56 W |
| Tamms | Populated Place | 104 | Alexander | 37 14 06 N | 089 16 12 W |
| Tamms Election Precinct | Civil | 104 | Alexander | 37 14 25 N | 089 16 46 W |
| Tampico | Populated Place | 195 | Whiteside | 41 37 49 N | 089 47 10 W |