Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Armstrongs Store (historical) | Building | 336 | Texas | 37 16 55 N | 092 06 20 W |
| Arnault Branch | Stream | | Washington | 38 03 20 N | 090 48 43 W |
| Arnault Branch Mine Dam | Dam | 276 | Washington | 38 01 00 N | 090 49 42 W |
| Arnault Church | Church | 307 | Washington | 38 00 08 N | 090 49 19 W |
| Arnault School (historical) | School | 244 | Washington | 38 00 55 N | 090 48 27 W |
| Arnett | Populated Place | 419 | McDonald | 36 33 45 N | 094 13 20 W |
| Arnett Cemetery | Cemetery | 239 | Madison | 37 32 19 N | 090 17 26 W |
| Arnett Mountain | Summit | 380 | Madison | 37 28 13 N | 090 26 03 W |
| Arnett School (historical) | School | 238 | Howard | 39 05 57 N | 092 31 35 W |
| Arney Lake Dam | Dam | 279 | Harrison | 40 17 36 N | 093 49 01 W |
| Arnhold Ridge | Ridge | 256 | Camden | 38 04 41 N | 092 50 01 W |
| Arnica | Populated Place | 285 | Cedar | 37 45 06 N | 093 42 31 W |
| Arnica School | School | 302 | Cedar | 37 45 19 N | 093 42 49 W |
| Arnika Ranch Airport | Airport | 350 | Douglas | 36 58 30 N | 092 32 34 W |
| Arno | Populated Place | 328 | Douglas | 36 56 23 N | 092 44 50 W |
| Arno Kreter Lake | Reservoir | 259 | Gasconade | 38 15 36 N | 091 28 01 W |
| Arno School (historical) | School | 327 | Douglas | 36 56 23 N | 092 44 51 W |
| Arnold | Populated Place | 184 | Jefferson | 38 25 58 N | 090 22 39 W |
| Arnold Branch | Stream | | Camden | 37 57 33 N | 092 39 34 W |
| Arnold Branch | Stream | | Ozark | 36 44 16 N | 092 10 18 W |
| Arnold Cemetery | Cemetery | 253 | Camden | 38 08 50 N | 092 37 24 W |
| Arnold Cemetery | Cemetery | 135 | Ripley | 36 38 49 N | 090 37 34 W |
| Arnold Cemetery | Cemetery | 235 | Washington | 38 11 17 N | 090 52 31 W |
| Arnold Chapel (historical) | Church | 445 | Lawrence | 36 56 32 N | 093 52 53 W |
| Arnold Church | Church | 173 | Jefferson | 38 24 27 N | 090 22 15 W |
| Arnold City Park | Park | 124 | St. Louis | 38 27 08 N | 090 21 11 W |
| Arnold Creek | Stream | | Washington | 38 11 20 N | 090 52 45 W |
| Arnold Creek | Stream | | Washington | 38 11 17 N | 090 52 52 W |
| Arnold Ford (historical) | Locale | 279 | Stone | 36 35 23 N | 093 31 33 W |
| Arnold Hollow | Valley | | Miller | 38 13 06 N | 092 33 43 W |
| Arnold Park | Park | 129 | St. Louis | 38 25 35 N | 090 21 28 W |
| Arnold School | School | 231 | Boone | 38 42 21 N | 092 18 07 W |
| Arnold School (historical) | School | 244 | Boone | 38 42 46 N | 092 16 49 W |
| Arnold School (historical) | School | 300 | Daviess | 39 58 33 N | 093 46 51 W |
| Arnoldsville School (historical) | School | 315 | Buchanan | 39 32 32 N | 094 44 52 W |
| Arnot Lake Dam | Dam | 218 | St. Charles | 38 42 54 N | 090 51 42 W |
| Arnsberg | Populated Place | 146 | Cape Girardeau | 37 34 11 N | 089 46 39 W |
| Arnsberg Community Park | Park | 153 | Cape Girardeau | 37 34 06 N | 089 47 45 W |
| Arnsberg School (historical) | School | 152 | Cape Girardeau | 37 34 05 N | 089 47 45 W |
| Aroma | Populated Place | 373 | Newton | 36 51 49 N | 094 15 53 W |
| Around Town Center | Locale | 321 | Jasper | 37 03 31 N | 094 28 40 W |
| Arp Choille Company Section 23 Dam | Dam | 191 | St. Charles | 38 38 18 N | 090 53 00 W |
| Arphart Church | Church | 442 | Barry | 36 48 18 N | 093 52 43 W |
| Arrarat School (historical) | School | 287 | St. Clair | 37 54 36 N | 093 55 36 W |
| Arrington School | School | 333 | Harrison | 40 30 29 N | 094 05 52 W |
| Arroll | Populated Place | 366 | Texas | 37 06 27 N | 091 43 36 W |
| Arroll School | School | 348 | Texas | 37 06 01 N | 091 43 36 W |
| Arrow Head Lake | Reservoir | 322 | Howell | 36 39 24 N | 091 53 07 W |
| Arrow Point | Populated Place | 324 | Barry | 36 32 41 N | 093 37 10 W |
| Arrow Rock | Populated Place | 216 | Saline | 39 04 11 N | 092 56 48 W |
| Arrow Rock State Historic Site | Park | 214 | Saline | 39 03 54 N | 092 56 32 W |
| Arrowhead | Populated Place | 252 | Miller | 38 10 52 N | 092 37 42 W |
| Arrowhead Airport | Airport | 137 | St. Louis | 38 41 30 N | 090 31 00 W |
| Arrowhead Beach | Populated Place | 248 | Miller | 38 10 48 N | 092 37 47 W |
| Arrowhead Estates Lower Dam | Dam | 147 | St. Louis | 38 40 06 N | 090 33 06 W |
| Arrowhead Estates Lower Lake | Reservoir | 147 | St. Louis | 38 40 06 N | 090 33 06 W |
| Arrowhead Estates Upper Dam | Dam | 170 | St. Louis | 38 40 00 N | 090 32 54 W |
| Arrowhead Golf Course | Locale | 173 | St. Louis | 38 25 48 N | 090 19 48 W |
| Arrowhead Lake Upper Dam | Dam | 353 | Dent | 37 42 00 N | 091 30 13 W |
| Arrowhead Lakes | Reservoir | 326 | Howell | 36 39 26 N | 091 53 13 W |
| Arrowhead Lakes Lower Dam | Dam | 352 | Dent | 37 41 54 N | 091 30 07 W |
| Arrowhead Stadium | Park | 262 | Jackson | 39 02 57 N | 094 29 04 W |
| Arroyo (historical) | Locale | 315 | Phelps | 37 51 58 N | 091 57 49 W |
| Arsenal Hill | Summit | 277 | Clay | 39 11 56 N | 094 24 24 W |
| Art (historical) | Locale | 317 | Newton | 36 49 05 N | 094 28 49 W |
| Art Institute | School | 283 | Jackson | 39 02 49 N | 094 34 59 W |
| Artesian Branch | Stream | | Lewis | 40 10 24 N | 091 30 54 W |
| Artesian Lake | Reservoir | 220 | Washington | 38 10 24 N | 090 52 42 W |
| Artesian Lake Dam | Dam | 220 | Washington | 38 10 24 N | 090 52 42 W |
| Artesian Well (historical) | Well | 93 | Stoddard | 36 57 41 N | 089 46 16 W |
| Arthur | Populated Place | 232 | Vernon | 38 00 47 N | 094 22 10 W |
| Arthur Cemetery | Cemetery | 317 | Jasper | 37 10 37 N | 094 09 38 W |
| Arthur Creek | Stream | | Texas | 37 25 47 N | 091 56 48 W |
| Arthur Creek School | School | 350 | Texas | 37 24 27 N | 091 56 09 W |
| Arthur Iron Bank (historical) | Mine | 329 | Crawford | 37 50 01 N | 091 24 18 W |
| Arthur Jasper Lake | Reservoir | 194 | Gasconade | 38 37 54 N | 091 25 37 W |
| Arthur School | School | 232 | Vernon | 38 00 50 N | 094 22 15 W |
| Arthur School (historical) | School | 308 | Jasper | 37 10 12 N | 094 09 55 W |
| Arthur Scott Dam | Dam | 340 | Worth | 40 33 12 N | 094 36 25 W |
| Arthur Scott Lake | Reservoir | 340 | Worth | 40 33 12 N | 094 36 25 W |
| Arthur Spring | Spring | 238 | Gasconade | 38 12 31 N | 091 34 09 W |
| Arthur Spring Ford | Populated Place | 235 | Gasconade | 38 12 21 N | 091 34 05 W |
| Artz-Wenzel Cemetery | Cemetery | 283 | Miller | 38 17 53 N | 092 33 45 W |
| Arvin Ranch Airport | Airport | 303 | Bates | 38 26 25 N | 094 35 36 W |
| Arytown Church | Church | 283 | Oregon | 36 33 14 N | 091 22 46 W |
| Arytown Church | Church | 294 | Oregon | 36 32 57 N | 091 23 53 W |
| Asarco Lake | Reservoir | 262 | Iron | 37 29 30 N | 090 41 12 W |
| Asarco Lake Dam | Dam | 262 | Iron | 37 29 30 N | 090 41 12 W |
| Asarco Section 11 Lower Dam | Dam | 277 | Iron | 37 28 36 N | 090 41 06 W |
| Asarco Section 11 Upper Dam | Dam | 280 | Iron | 37 28 30 N | 090 40 54 W |
| ASB Bridge | Bridge | 220 | Clay | 39 07 01 N | 094 34 48 W |
| Asbell Cemetery | Cemetery | 312 | Dade | 37 32 07 N | 093 39 29 W |
| Asbridge Hollow | Valley | | Dent | 37 27 00 N | 091 26 03 W |
| Asbury | Populated Place | 274 | Jasper | 37 16 28 N | 094 36 20 W |
| Asbury Chapel | Church | 221 | Lewis | 39 56 55 N | 091 51 07 W |
| Asbury Church | Church | 236 | Chariton | 39 21 25 N | 092 53 51 W |
| Asbury Church | Church | 229 | Clark | 40 34 39 N | 091 56 17 W |
| Asbury Church | Church | 296 | Sullivan | 40 15 20 N | 093 16 22 W |
| Asbury Farms Dam | Dam | 261 | Jasper | 37 17 18 N | 094 32 01 W |
| Asbury Farms Lake | Reservoir | 261 | Jasper | 37 17 18 N | 094 32 01 W |
| Asbury School | School | 272 | Jasper | 37 16 29 N | 094 35 47 W |
| Ascalon | Populated Place | 200 | St. Louis | 38 42 03 N | 090 24 34 W |
| Ascension Church | Church | 156 | St. Louis (city) | 38 39 28 N | 090 17 08 W |
| Ascraft Church (historical) | Church | 98 | Butler | 36 41 31 N | 090 22 29 W |
| Ash | Populated Place | 245 | Monroe | 39 30 54 N | 092 17 24 W |
| Ash Disposal Pond | Reservoir | 143 | Franklin | 38 33 06 N | 090 50 24 W |
| Ash Ditch | Canal | 90 | New Madrid | 36 48 36 N | 089 29 34 W |
| Ash Ditch | Canal | 90 | New Madrid | 36 48 54 N | 089 29 34 W |
| Ash Grove | Populated Place | 319 | Greene | 37 18 55 N | 093 35 07 W |
| Ash Grove School (historical) | School | 311 | Clinton | 39 43 34 N | 094 31 03 W |