Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Martin Luther King Community Center | Building | 171 | Rock Island | 41 30 12 N | 090 35 09 W |
| Martin Luther King Junior Laboratory School | School | 182 | Cook | 42 03 16 N | 087 41 46 W |
| Martin Luther King Junior Memorial Bridge | Bridge | 119 | St. Clair | 38 37 51 N | 090 10 43 W |
| Martin Luther King Junior University Union | Building | 213 | Coles | 39 28 53 N | 088 10 31 W |
| Martin Luther King Park | Park | 185 | Cook | 41 35 47 N | 087 39 06 W |
| Martin Luther King Park | Park | 248 | McLean | 40 30 47 N | 088 57 35 W |
| Martin Luther King School | School | 226 | Winnebago | 42 15 34 N | 089 06 07 W |
| Martin Luther Lutheran Church | Church | 195 | Cook | 41 56 44 N | 087 47 53 W |
| Martin Memorial Park | Park | 216 | Winnebago | 42 18 50 N | 089 04 04 W |
| Martin Mine | Mine | 134 | Hardin | 37 28 44 N | 088 20 55 W |
| Martin Park | Park | 190 | Cook | 41 43 42 N | 087 48 51 W |
| Martin Park | Park | 230 | Knox | 40 56 39 N | 090 18 44 W |
| Martin Prairie School (historical) | School | 181 | Greene | 39 29 48 N | 090 16 58 W |
| Martin RLA Airport | Airport | 219 | De Witt | 40 06 34 N | 088 49 43 W |
| Martin School (historical) | School | 222 | Champaign | 40 22 14 N | 087 59 23 W |
| Martin School (historical) | School | 134 | Franklin | 38 06 44 N | 089 00 38 W |
| Martin School (historical) | School | 176 | Kendall | 41 28 32 N | 088 20 54 W |
| Martin School (historical) | School | 216 | McDonough | 40 28 14 N | 090 48 34 W |
| Martin School (historical) | School | 212 | McDonough | 40 26 51 N | 090 52 58 W |
| Martin School (historical) | School | 176 | Sangamon | 39 41 04 N | 089 27 27 W |
| Martin T Snyder Memorial Nature Preserve | Park | 139 | Clay | 38 38 15 N | 088 31 50 W |
| Martin Tarble Lake | Reservoir | 204 | Clark | 39 28 18 N | 087 50 24 W |
| Martin Tarble Lake Dam | Dam | 204 | Clark | 39 28 18 N | 087 50 24 W |
| Martin Temple African Methodist Episcopal Zion Church | Church | 179 | Cook | 41 45 50 N | 087 37 13 W |
| Martin Temple Christian Methodist Episcopal Church (historical) | Church | 96 | Alexander | 37 00 33 N | 089 10 38 W |
| Martin Towhead | Island | 128 | Calhoun | 38 54 54 N | 090 38 48 W |
| Martin Van Lucas School (historical) | School | 124 | St. Clair | 38 36 22 N | 090 09 32 W |
| Martini Cemetery | Cemetery | 167 | Monroe | 38 20 46 N | 090 05 29 W |
| Martini School (historical) | School | 165 | Monroe | 38 20 45 N | 090 05 28 W |
| Martins Airport | Airport | 210 | Hancock | 40 24 09 N | 091 09 55 W |
| Martins Prairie Cemetery | Cemetery | 184 | Greene | 39 29 52 N | 090 17 00 W |
| Martins Prairie Church | Church | 180 | Greene | 39 29 01 N | 090 16 57 W |
| Martins Store (historical) | Locale | 134 | Hamilton | 38 03 33 N | 088 26 16 W |
| Martinsburg | Populated Place | 219 | Pike | 39 30 57 N | 090 50 33 W |
| Martinsville | Populated Place | 186 | Clark | 39 20 08 N | 087 52 55 W |
| Martinsville Bible Church | Church | 184 | Clark | 39 20 03 N | 087 52 55 W |
| Martinsville Christian Church | Church | 183 | Clark | 39 20 19 N | 087 53 06 W |
| Martinsville Elementary School | School | 185 | Clark | 39 20 22 N | 087 52 47 W |
| Martinsville High School | School | 184 | Clark | 39 19 59 N | 087 53 14 W |
| Martinsville Post Office | Post Office | 184 | Clark | 39 20 00 N | 087 52 57 W |
| Martinsville United Methodist Church | Church | 187 | Clark | 39 20 05 N | 087 53 06 W |
| Martinton | Populated Place | 191 | Iroquois | 40 54 57 N | 087 43 31 W |
| Martinton Ditch Number 3 | Canal | 190 | Iroquois | 40 53 51 N | 087 40 53 W |
| Martner School (historical) | School | 222 | Kendall | 41 35 33 N | 088 28 30 W |
| Marvin D Bradd Airport | Airport | 241 | Piatt | 40 16 18 N | 088 29 40 W |
| Marvin Puzey Lake | Reservoir | 197 | Vermilion | 40 03 48 N | 087 50 48 W |
| Marvin Puzey Lake Dam | Dam | 197 | Vermilion | 40 03 48 N | 087 50 48 W |
| Marx V Stott Airport | Airport | 268 | DeKalb | 41 58 56 N | 088 48 40 W |
| Mary Roberts School of Beauty Culture | School | 187 | Cook | 41 46 39 N | 087 46 25 W |
| Mary Alice Park | Park | 229 | Champaign | 40 18 24 N | 088 09 43 W |
| Mary Crane Nursery School | School | 180 | Cook | 41 56 04 N | 087 40 58 W |
| Mary D Ayer Park | Park | 283 | McHenry | 42 25 06 N | 088 37 09 W |
| Mary Egan Park | Park | 229 | DuPage | 41 47 42 N | 087 58 32 W |
| Mary F Butler Memorial African Methodist Episcopal Church | Church | 181 | Cook | 41 52 36 N | 087 41 47 W |
| Mary Hall (historical) | Building | 181 | Cook | 41 56 17 N | 087 38 45 W |
| Mary Hegeler Carus Park | Park | 159 | La Salle | 41 19 54 N | 089 05 05 W |
| Mary J Booth Library | Building | 212 | Coles | 39 28 48 N | 088 10 32 W |
| Mary Lous Academy of Movement | School | 189 | Cook | 41 57 11 N | 087 46 38 W |
| Mary Magdalene Missionary Baptist Church | Church | 184 | Cook | 41 41 42 N | 087 37 33 W |
| Mary Martha Hall and Computer Center | Building | 192 | Cook | 41 53 57 N | 087 48 29 W |
| Mary McGaw Hall | Building | 248 | Winnebago | 42 16 20 N | 089 00 58 W |
| Mary Meadows | Populated Place | 277 | Kane | 41 56 18 N | 088 26 48 W |
| Mary Meyer School | School | 181 | Cook | 41 55 59 N | 087 38 28 W |
| Mary Miller Junior High School | School | 204 | Vermilion | 39 58 30 N | 087 37 48 W |
| Mary Morgan Elementary School | School | 222 | Ogle | 42 07 47 N | 089 15 53 W |
| Mary Queen of Heaven Church | Church | 185 | Cook | 41 50 50 N | 087 45 25 W |
| Mary Queen of Heaven Church | Church | 212 | DuPage | 41 54 39 N | 087 57 34 W |
| Mary Queen of Heaven School | School | 212 | DuPage | 41 54 40 N | 087 57 36 W |
| Mary Queen of Heaven School (historical) | School | 185 | Cook | 41 50 49 N | 087 45 25 W |
| Mary Seat of Wisdom Church | Church | 193 | Cook | 41 59 32 N | 087 50 14 W |
| Mary Seat of Wisdom School | School | 194 | Cook | 41 59 36 N | 087 50 15 W |
| Mary Thompson Hospital | Hospital | 182 | Cook | 41 53 05 N | 087 40 02 W |
| Mary W French Academy | School | 207 | Macon | 39 50 27 N | 088 57 47 W |
| Mary's Circle | Park | 189 | Cook | 41 42 29 N | 087 42 51 W |
| Marya Yates Elementary School | School | 216 | Cook | 41 31 18 N | 087 45 54 W |
| Marycrest Elementary School | School | 193 | Will | 41 30 58 N | 088 08 19 W |
| Marycrest Park | Park | 222 | Cook | 41 33 21 N | 087 44 13 W |
| Marycrest Shopping Center | Locale | 201 | Kankakee | 41 07 10 N | 087 50 18 W |
| Marycrest Shopping Center | Locale | 195 | Will | 41 31 17 N | 088 08 00 W |
| Marydale | Populated Place | 141 | Clinton | 38 41 51 N | 089 22 19 W |
| Maryhill Cemetery | Cemetery | 201 | Cook | 42 02 09 N | 087 49 44 W |
| Maryknoll Seminary | School | 228 | DuPage | 41 51 23 N | 088 02 57 W |
| Maryland | Populated Place | 269 | Ogle | 42 03 56 N | 089 32 50 W |
| Maryland Place | Populated Place | 128 | Madison | 38 43 54 N | 090 06 36 W |
| Marys Chapel (historical) | Church | 155 | Hamilton | 38 02 05 N | 088 32 39 W |
| Marys Chapel Cemetery | Cemetery | 159 | Hamilton | 38 02 05 N | 088 32 34 W |
| Marys Chapel School (historical) | School | 130 | Hamilton | 38 01 33 N | 088 32 42 W |
| Marys River | Locale | 104 | Randolph | 37 52 45 N | 089 47 00 W |
| Marys River | Stream | | Randolph | 37 52 49 N | 089 46 59 W |
| Marys River Covered Bridge | Bridge | 116 | Randolph | 37 56 55 N | 089 45 57 W |
| Marysville Fishing Club Lake | Reservoir | 177 | Madison | 38 43 36 N | 089 57 00 W |
| Marysville Fishing Club Lake Dam | Dam | 177 | Madison | 38 43 36 N | 089 57 00 W |
| Marysville School (historical) | School | 191 | Kendall | 41 36 18 N | 088 18 59 W |
| Maryville | Populated Place | 176 | Madison | 38 43 25 N | 089 57 21 W |
| Maryville Assembly of God Church | Church | 178 | Madison | 38 43 51 N | 089 57 23 W |
| Maryville Cemetery | Cemetery | 187 | Fulton | 40 27 55 N | 090 05 27 W |
| Maryville City of Youth | School | 196 | Cook | 42 04 08 N | 087 53 39 W |
| Maryville Fire Station | Building | 177 | Madison | 38 43 31 N | 089 57 20 W |
| Maryville First Baptist Church | Church | 179 | Madison | 38 44 04 N | 089 56 52 W |
| Maryville High School | School | 175 | Madison | 38 43 28 N | 089 58 04 W |
| Marywood | Populated Place | 225 | Kane | 41 47 37 N | 088 17 25 W |
| Marywood Catholic Cemetery | Cemetery | 225 | Kane | 41 47 37 N | 088 17 30 W |
| Marywood High School | School | 185 | Cook | 42 03 24 N | 087 41 15 W |
| Mascoutah | Populated Place | 131 | St. Clair | 38 29 25 N | 089 47 35 W |
| Mascoutah Church of Christ | Church | 129 | St. Clair | 38 28 55 N | 089 47 36 W |
| Mascoutah City Cemetery | Cemetery | 133 | St. Clair | 38 29 57 N | 089 49 15 W |
| Mascoutah City Hall | Building | 129 | St. Clair | 38 29 26 N | 089 47 51 W |
| Mascoutah Community High School | School | 131 | St. Clair | 38 29 41 N | 089 49 09 W |
| Mascoutah Free Will Baptist Church | Church | 130 | St. Clair | 38 30 07 N | 089 48 29 W |
| Mascoutah Junior High School | School | 129 | St. Clair | 38 29 58 N | 089 48 22 W |