Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Johnston Police Department | Building | 254 | Polk | 41 40 25 N | 093 41 49 W |
| Johnston Post Office | Post Office | 253 | Polk | 41 40 03 N | 093 41 54 W |
| Johnston Public Library | Building | 254 | Polk | 41 40 25 N | 093 41 49 W |
| Johnstown Cemetery | Cemetery | 256 | Jones | 42 08 45 N | 091 02 05 W |
| Johnstown Post Office (historical) | Post Office | 314 | Appanoose | 40 44 22 N | 093 04 41 W |
| Joice | Locale | 384 | Worth | 43 21 48 N | 093 27 09 W |
| Joice | Populated Place | 385 | Worth | 43 21 46 N | 093 27 14 W |
| Joice Post Office | Post Office | 385 | Worth | 43 21 45 N | 093 27 13 W |
| Joice Public Library | Building | 384 | Worth | 43 21 47 N | 093 27 15 W |
| Joinerville County Park | Park | 223 | Jackson | 42 04 50 N | 090 45 08 W |
| Joint Drainage Ditch 16 | Canal | 369 | Calhoun | 42 25 02 N | 094 43 14 W |
| Joint Drainage Ditch 9-13 | Canal | 375 | Pocahontas | 42 34 29 N | 094 42 12 W |
| Joles Creek | Stream | | Clayton | 42 43 41 N | 091 08 38 W |
| Jolley | Populated Place | 375 | Calhoun | 42 28 44 N | 094 43 08 W |
| Jolley (historical) | Locale | 374 | Calhoun | 42 28 42 N | 094 43 15 W |
| Jolley Post Office | Post Office | 375 | Calhoun | 42 28 44 N | 094 43 08 W |
| Jolly Rogers Campground | Locale | 212 | Johnson | 41 48 15 N | 091 35 31 W |
| Jollyville Hill | Summit | 161 | Lee | 40 41 11 N | 091 14 10 W |
| Jollyville Post Office (historical) | Post Office | 203 | Lee | 40 41 13 N | 091 14 59 W |
| Jonathan Creek | Stream | | Decatur | 40 45 20 N | 093 38 07 W |
| Jonathan P Dolliver State Historical Marker | Park | 336 | Webster | 42 30 12 N | 094 11 04 W |
| Jonathan Woody Historical Marker | Park | 246 | Wapello | 41 03 14 N | 092 22 12 W |
| Jones Beach | Beach | 426 | Dickinson | 43 21 18 N | 095 09 46 W |
| Jones Branch | Stream | | Jefferson | 40 55 30 N | 091 48 14 W |
| Jones Cemetery | Cemetery | 248 | Keokuk | 41 12 00 N | 092 13 31 W |
| Jones Cemetery | Cemetery | 217 | Lee | 40 40 30 N | 091 20 36 W |
| Jones Cemetery | Cemetery | 201 | Van Buren | 40 38 42 N | 091 55 15 W |
| Jones Cemetery | Cemetery | 309 | Wayne | 40 52 50 N | 093 08 41 W |
| Jones Cemetery | Cemetery | 288 | Wayne | 40 48 04 N | 093 06 34 W |
| Jones Chiropractic Clinic | Hospital | 411 | Lyon | 43 25 50 N | 096 10 16 W |
| Jones Church | Church | 285 | Wayne | 40 48 05 N | 093 06 36 W |
| Jones County | Civil | 293 | Jones | 42 07 00 N | 091 08 01 W |
| Jones County Courthouse | Building | 252 | Jones | 42 06 33 N | 091 17 24 W |
| Jones County Sheriffs Office | Building | 252 | Jones | 42 06 33 N | 091 17 24 W |
| Jones Creek | Stream | | Allamakee | 43 17 50 N | 091 21 33 W |
| Jones Creek | Stream | | Madison | 41 17 18 N | 093 50 37 W |
| Jones Creek | Stream | | Scott | 41 45 35 N | 090 27 56 W |
| Jones Eye Clinic | Hospital | 351 | Woodbury | 42 32 44 N | 096 24 30 W |
| Jones Family Cemetery | Cemetery | 228 | Jefferson | 40 56 20 N | 091 49 31 W |
| Jones Junior High School | School | 269 | Dubuque | 42 30 02 N | 090 40 42 W |
| Jones Junior High School | School | 388 | Union | 41 03 59 N | 094 21 43 W |
| Jones Memorial Park | Park | 216 | Linn | 41 56 46 N | 091 38 52 W |
| Jones Park | Park | 336 | Hardin | 42 31 15 N | 093 15 36 W |
| Jones Park Cemetery | Cemetery | 344 | Hardin | 42 31 10 N | 093 10 31 W |
| Jones Park Golf Course | Locale | 216 | Linn | 41 56 45 N | 091 38 51 W |
| Jones Regional Medical Center | Hospital | 267 | Jones | 42 06 47 N | 091 17 17 W |
| Jones School | School | 332 | Clarke | 41 08 42 N | 093 50 45 W |
| Jones Siding | Populated Place | 328 | Humboldt | 42 40 48 N | 094 12 29 W |
| Jordan | Locale | 338 | Boone | 42 02 57 N | 093 47 03 W |
| Jordan | Populated Place | 338 | Boone | 42 02 57 N | 093 47 03 W |
| Jordan Cemetery | Cemetery | 423 | Monona | 42 00 28 N | 095 50 56 W |
| Jordan Cemetery | Cemetery | 289 | Polk | 41 33 32 N | 093 44 43 W |
| Jordan Creek | Stream | | Iowa | 41 37 59 N | 092 16 54 W |
| Jordan Creek | Stream | | Jefferson | 41 03 45 N | 092 14 17 W |
| Jordan Creek | Stream | | Johnson | 41 47 50 N | 091 31 22 W |
| Jordan Creek | Stream | | Monona | 41 54 45 N | 095 51 16 W |
| Jordan Creek | Stream | | O'Brien | 42 59 06 N | 095 25 58 W |
| Jordan Creek | Stream | | Polk | 41 33 31 N | 093 43 02 W |
| Jordan Creek | Stream | | Pottawattamie | 41 10 21 N | 095 22 28 W |
| Jordan Creek | Stream | | Tama | 42 01 34 N | 092 35 46 W |
| Jordan Creek | Stream | | Wayne | 40 48 13 N | 093 12 54 W |
| Jordan Creek Elementary School | School | 291 | Polk | 41 33 35 N | 093 45 26 W |
| Jordan Creek Park | Park | 276 | Polk | 41 34 00 N | 093 44 41 W |
| Jordan Hall | Building | 266 | Marion | 41 24 03 N | 092 55 05 W |
| Jordan House | Building | 256 | Polk | 41 33 35 N | 093 44 07 W |
| Jordan Park | Park | 286 | Polk | 41 31 55 N | 093 36 14 W |
| Jordan Post Office (historical) | Post Office | 338 | Boone | 42 02 57 N | 093 47 03 W |
| Jordan United Methodist Church | Church | 242 | Polk | 41 34 16 N | 093 36 36 W |
| Jordan's Grove Cemetery | Cemetery | 297 | Linn | 42 09 09 N | 091 29 60 W |
| Jordans Grove | Populated Place | 298 | Linn | 42 09 21 N | 091 29 55 W |
| Joseph J Baum Memorial Park | Park | 287 | Delaware | 42 29 10 N | 091 26 42 W |
| Joseph Patterson Historical Marker | Park | 182 | Lee | 40 24 05 N | 091 24 21 W |
| Joslyn Chiropractic Clinic | Hospital | 396 | Howard | 43 22 28 N | 092 07 01 W |
| Joy Baptist Church | Church | 169 | Lee | 40 37 56 N | 091 18 37 W |
| Joy Creek | Stream | | Plymouth | 42 40 08 N | 096 33 16 W |
| Joy School | School | 375 | Woodbury | 42 28 57 N | 096 21 50 W |
| Joy Springs County Park | Park | 323 | Clayton | 42 40 24 N | 091 35 56 W |
| Joyce Island | Island | 180 | Clinton | 41 51 25 N | 090 10 50 W |
| Joyce Lake | Lake | 186 | Allamakee | 43 12 52 N | 091 07 58 W |
| Joyce Park | Park | 201 | Lee | 40 24 58 N | 091 24 13 W |
| Juanita (historical) | Locale | 423 | Buena Vista | 42 34 49 N | 095 08 53 W |
| Jubilee | Populated Place | 272 | Black Hawk | 42 23 03 N | 092 06 14 W |
| Jubilee Christian Fellowship | Church | 234 | Jefferson | 41 00 23 N | 091 57 54 W |
| Jubilee Family Church | Church | 256 | Mahaska | 41 17 32 N | 092 38 60 W |
| Jubilee Fellowship Church | Church | 250 | Polk | 41 37 09 N | 093 32 36 W |
| Jubilee Post Office (historical) | Post Office | 272 | Black Hawk | 42 23 03 N | 092 06 14 W |
| Jubilee United Methodist Church | Church | 262 | Black Hawk | 42 29 30 N | 092 20 39 W |
| Judd | Populated Place | 339 | Webster | 42 28 20 N | 094 02 59 W |
| Judd (historical) | Locale | 339 | Webster | 42 28 20 N | 094 02 59 W |
| Judd Post Office (historical) | Post Office | 339 | Webster | 42 28 20 N | 094 02 59 W |
| Judd Wildlife Area | Park | 419 | Dickinson | 43 16 50 N | 095 11 36 W |
| Judge Lewis Field-Mount Ayr Municipal Airport | Airport | 372 | Ringgold | 40 42 20 N | 094 13 26 W |
| Judge Lewis Park | Park | 364 | Ringgold | 40 42 45 N | 094 14 57 W |
| Judge School | School | 258 | Monroe | 41 01 45 N | 093 00 24 W |
| Judicial Ditch Number 64 | Canal | 444 | Osceola | 43 22 02 N | 095 30 06 W |
| Judicial Ditch Number 64 | Canal | 458 | Osceola | 43 25 07 N | 095 28 18 W |
| Judicial Ditch Number 7 | Canal | 344 | Kossuth | 43 29 54 N | 094 14 55 W |
| Julia O'Neil Park | Park | 338 | Hardin | 42 31 17 N | 093 14 49 W |
| Julian | Locale | 271 | Dubuque | 42 28 55 N | 090 46 45 W |
| Julian Post Office (historical) | Post Office | 271 | Dubuque | 42 28 55 N | 090 46 45 W |
| Julien | Populated Place | 275 | Dubuque | 42 28 52 N | 090 46 46 W |
| Julien Dubuque Bridge | Bridge | 180 | Dubuque | 42 29 30 N | 090 39 15 W |
| Julien Dubuque Monument | Park | 201 | Dubuque | 42 28 07 N | 090 38 45 W |
| Julien Post Office (historical) | Post Office | 275 | Dubuque | 42 28 52 N | 090 46 46 W |
| Junction (historical) | Populated Place | 332 | Winneshiek | 43 05 07 N | 091 37 46 W |
| Junction City Post Office (historical) | Post Office | 292 | Mills | 41 00 07 N | 095 51 50 W |
| Junction School | School | 317 | Boone | 41 56 11 N | 094 01 42 W |
| Junction Switch | Populated Place | 255 | Jones | 42 16 36 N | 091 12 11 W |
| Junge Park | Park | 191 | Scott | 41 33 14 N | 090 34 44 W |
| Jungletown Public Access | Locale | 229 | Jones | 41 59 50 N | 091 03 22 W |