Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Meridian Junior High School | School | 215 | Ogle | 42 06 29 N | 089 10 52 W |
| Meridian Middle School | School | 192 | Macon | 39 41 42 N | 089 07 18 W |
| Meridian School (historical) | School | 253 | Ogle | 42 02 09 N | 089 10 21 W |
| Meridian School (historical) | School | 219 | Warren | 40 47 27 N | 090 43 52 W |
| Meridian School (historical) | School | 227 | Woodford | 40 42 47 N | 089 09 27 W |
| Meridian Senior High School | School | 219 | Macon | 39 42 10 N | 088 59 48 W |
| Meridians Cemetery | Cemetery | 214 | Warren | 40 47 51 N | 090 29 38 W |
| Merit Club Golf Course | Locale | 222 | Lake | 42 20 14 N | 087 57 55 W |
| Merit School (historical) | School | 206 | Moultrie | 39 40 51 N | 088 33 58 W |
| Merkle Engineers Airport | Airport | 299 | Jo Daviess | 42 17 20 N | 090 20 43 W |
| Merkle School (historical) | School | 205 | Edgar | 39 41 16 N | 087 53 44 W |
| Merkle School (historical) | School | 197 | Iroquois | 40 50 26 N | 087 56 25 W |
| Merkle School (historical) | School | 201 | Montgomery | 39 15 01 N | 089 11 05 W |
| Merle Reskin Theatre | Building | 180 | Cook | 41 52 26 N | 087 37 30 W |
| Merlin Park | Park | 222 | DuPage | 41 47 26 N | 087 56 37 W |
| Mermet | Populated Place | 105 | Massac | 37 16 23 N | 088 50 46 W |
| Mermet Lake | Reservoir | 104 | Massac | 37 15 18 N | 088 50 56 W |
| Mermet Lake State Conservation Area | Park | 104 | Massac | 37 15 44 N | 088 51 02 W |
| Mermet Swamp Nature Preserve | Park | 104 | Massac | 37 14 53 N | 088 49 40 W |
| Merna | Populated Place | 247 | McLean | 40 31 00 N | 088 49 33 W |
| Merna Cemetery | Cemetery | 247 | McLean | 40 30 59 N | 088 48 21 W |
| Merna School (historical) | School | 250 | McLean | 40 30 05 N | 088 49 33 W |
| Merner Field House | Building | 205 | DuPage | 41 46 11 N | 088 08 38 W |
| Merom Ferry | Locale | 126 | Crawford | 39 03 26 N | 087 34 23 W |
| Merriam | Populated Place | 127 | Wayne | 38 21 45 N | 088 16 38 W |
| Merriam Center for Public Administration | Building | 180 | Cook | 41 47 08 N | 087 35 34 W |
| Merriam Elementary School | School | 135 | Wayne | 38 22 34 N | 088 16 35 W |
| Merriam Laboratory | Building | 224 | Champaign | 40 06 26 N | 088 13 51 W |
| Merriam School (historical) | School | 134 | Wayne | 38 21 03 N | 088 16 39 W |
| Merrick Park | Park | 184 | Cook | 42 02 38 N | 087 41 14 W |
| Merrick Park | Park | 187 | Cook | 41 53 17 N | 087 45 42 W |
| Merrill C Meigs Airport (historical) | Airport | 178 | Cook | 41 51 31 N | 087 36 28 W |
| Merrill Elementary School | School | 197 | Whiteside | 41 46 36 N | 089 41 31 W |
| Merrill J Holmes Administration Building | Building | 247 | McLean | 40 29 29 N | 088 59 26 W |
| Merrill Park | Park | 178 | Cook | 41 43 11 N | 087 34 18 W |
| Merrill Residence Hall | Building | 212 | Lake | 42 13 58 N | 087 49 50 W |
| Merrill School | School | 194 | Cook | 41 59 24 N | 087 50 09 W |
| Merrill School (historical) | School | 212 | Cook | 42 08 22 N | 087 58 02 W |
| Merrimac | Populated Place | 123 | Monroe | 38 22 15 N | 090 20 00 W |
| Merrimac Park | Park | 190 | Cook | 41 57 07 N | 087 47 08 W |
| Merriner Park | Park | 173 | La Salle | 41 07 07 N | 088 50 26 W |
| Merrionette Manor (subdivision) | Populated Place | 180 | Cook | 41 43 15 N | 087 33 59 W |
| Merrionette Park | Populated Place | 189 | Cook | 41 41 03 N | 087 42 01 W |
| Merrionette Park Shopping Center | Locale | 189 | Cook | 41 40 59 N | 087 42 16 W |
| Merrionette Park Village Hall | Building | 190 | Cook | 41 41 02 N | 087 41 55 W |
| Merritt | Populated Place | 183 | Scott | 39 42 52 N | 090 24 57 W |
| Merritt Election Precinct | Civil | 180 | Scott | 39 43 28 N | 090 25 33 W |
| Merritt Farm (historical) | Locale | 235 | Winnebago | 42 13 38 N | 088 58 00 W |
| Merritt School (historical) | School | 146 | Marshall | 41 05 23 N | 089 23 58 W |
| Merry Cemetery | Cemetery | 166 | Effingham | 38 57 36 N | 088 26 38 W |
| Merry Dell School (historical) | School | 161 | Henderson | 40 51 54 N | 091 01 46 W |
| Merry Go Round Nursery School | School | 184 | Cook | 41 46 43 N | 087 41 46 W |
| Merry School (historical) | School | 218 | Champaign | 39 57 06 N | 088 15 17 W |
| Merry Widow Mine | Mine | 211 | Jo Daviess | 42 24 33 N | 090 28 10 W |
| Merryman Cemetery (historical) | Cemetery | 214 | Mercer | 41 15 04 N | 090 29 45 W |
| Merryman School (historical) | School | 223 | Mercer | 41 15 17 N | 090 29 58 W |
| Mertz Hall | Building | 185 | Cook | 42 00 04 N | 087 39 37 W |
| Mertz Memorial Park | Park | 228 | DuPage | 41 46 36 N | 087 58 09 W |
| Merwin Art Gallery | Building | 247 | McLean | 40 29 22 N | 088 59 31 W |
| Merwin Park | Park | 165 | Madison | 38 43 25 N | 089 40 29 W |
| Mesa Lake | Reservoir | 142 | Wabash | 38 31 51 N | 087 51 40 W |
| Mesa Lake Dam | Dam | 142 | Wabash | 38 31 51 N | 087 51 40 W |
| Mescher School (historical) | School | 133 | Clinton | 38 31 44 N | 089 30 27 W |
| Meshach Lake | Reservoir | 195 | Macoupin | 39 06 41 N | 089 57 39 W |
| Meskimmon School (historical) | School | 153 | Crawford | 38 57 24 N | 087 40 07 W |
| Messenger Cemetery | Cemetery | 170 | St. Clair | 38 32 57 N | 089 57 55 W |
| Messenger Woods County Forest Preserve | Park | 212 | Will | 41 34 33 N | 087 57 09 W |
| Messenger Woods Nature Preserve | Park | 235 | Will | 41 34 56 N | 087 57 55 W |
| Messer Cemetery | Cemetery | 222 | McLean | 40 39 35 N | 088 58 02 W |
| Messerer Cemetery | Cemetery | 205 | Schuyler | 40 05 25 N | 090 26 53 W |
| Messiah and Saint Bartholomew Episcopal Church | Church | 180 | Cook | 41 44 40 N | 087 35 20 W |
| Messiah Baptist Church | Church | 186 | Cook | 41 42 17 N | 087 38 35 W |
| Messiah Christian Church | Church | 128 | Marion | 37 43 13 N | 088 55 30 W |
| Messiah Evangelical Lutheran Church | Church | 203 | Whiteside | 41 48 04 N | 089 42 14 W |
| Messiah Lutheran Church | Church | 141 | Clinton | 38 36 55 N | 089 22 28 W |
| Messiah Lutheran Church | Church | 188 | Cook | 41 46 48 N | 087 46 04 W |
| Messiah Lutheran Church | Church | 183 | Cook | 41 46 40 N | 087 40 18 W |
| Messiah Lutheran Church | Church | 190 | Cook | 41 56 48 N | 087 46 55 W |
| Messiah Lutheran Church | Church | 196 | Cook | 42 02 12 N | 087 51 03 W |
| Messiah Lutheran Church | Church | 203 | DuPage | 41 52 03 N | 087 56 25 W |
| Messiah Lutheran Church | Church | 259 | Henry | 41 09 46 N | 090 02 47 W |
| Messiah Lutheran Church | Church | 245 | Kane | 42 04 26 N | 088 17 30 W |
| Messiah Lutheran Church | Church | 225 | Mercer | 41 12 10 N | 090 44 37 W |
| Messiah Lutheran Church | Church | 183 | Rock Island | 41 37 02 N | 090 20 03 W |
| Messiah Lutheran Church | Church | 176 | Will | 41 31 17 N | 088 10 08 W |
| Messiah Lutheran Church | Church | 248 | Winnebago | 42 16 41 N | 089 08 52 W |
| Messiah Lutheran Church Fellowship Hall | Church | 190 | Cook | 41 56 48 N | 087 46 55 W |
| Messiah Park | Park | 197 | Cook | 42 02 17 N | 087 51 02 W |
| Messiah School | School | 190 | Cook | 41 56 49 N | 087 46 54 W |
| Metamora | Populated Place | 249 | Woodford | 40 47 26 N | 089 21 38 W |
| Metamora City Hall | Building | 250 | Woodford | 40 47 26 N | 089 21 41 W |
| Metamora Courthouse | Building | 250 | Woodford | 40 47 30 N | 089 21 43 W |
| Metamora Fire Station | Building | 249 | Woodford | 40 47 22 N | 089 21 41 W |
| Metamora Grade School | School | 247 | Woodford | 40 47 37 N | 089 21 13 W |
| Metamora High School | School | 244 | Woodford | 40 47 42 N | 089 21 49 W |
| Metcalf | Populated Place | 210 | Edgar | 39 48 04 N | 087 48 26 W |
| Metcalf Christian Church | Church | 207 | Edgar | 39 48 16 N | 087 48 26 W |
| Metcalf School | School | 241 | McLean | 40 30 33 N | 088 59 37 W |
| Metcalf School (historical) | School | 152 | Bond | 38 47 49 N | 089 25 39 W |
| Metcalf School (historical) | School | 137 | Hamilton | 38 06 27 N | 088 23 29 W |
| Metcalf School (historical) | School | 166 | Marion | 38 35 01 N | 088 49 40 W |
| Metcalfe Magnet School | School | 187 | Cook | 41 40 09 N | 087 38 01 W |
| Methodist Cemetery | Cemetery | 221 | Clark | 39 27 37 N | 087 59 34 W |
| Methodist Cemetery | Cemetery | 224 | Shelby | 39 25 28 N | 088 58 28 W |
| Methodist Hospital of Chicago | Hospital | 183 | Cook | 41 58 22 N | 087 40 15 W |
| Methodist Medical Center of Illinois | Hospital | 176 | Peoria | 40 42 03 N | 089 35 42 W |
| Methodist Medical Center of Illinois Heliport | Airport | 173 | Peoria | 40 42 02 N | 089 35 41 W |
| Methodist Park | Park | 206 | Cook | 42 05 08 N | 087 57 35 W |
| Methodist Park | Park | 231 | DuPage | 41 47 13 N | 088 03 31 W |
| Metro Centre Shopping Center | Locale | 208 | Peoria | 40 44 38 N | 089 36 41 W |