Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Jewell | Locale | 321 | Hamilton | 42 18 42 N | 093 38 31 W |
| Jewell | Locale | 302 | Mills | 41 03 05 N | 095 36 56 W |
| Jewell | Populated Place | 322 | Hamilton | 42 18 25 N | 093 38 25 W |
| Jewell City Hall | Building | 323 | Hamilton | 42 18 30 N | 093 38 25 W |
| Jewell Fire Department | Building | 322 | Hamilton | 42 18 28 N | 093 38 29 W |
| Jewell Golf and Country Club | Locale | 320 | Hamilton | 42 18 50 N | 093 38 31 W |
| Jewell Police Department | Building | 323 | Hamilton | 42 18 30 N | 093 38 25 W |
| Jewell Post Office | Post Office | 322 | Hamilton | 42 18 24 N | 093 38 25 W |
| Jewell Post Office (historical) | Post Office | 346 | Mills | 41 03 10 N | 095 36 01 W |
| Jewett Elementary School | School | 256 | Black Hawk | 42 28 03 N | 092 17 04 W |
| Jewett Residence Hall | Building | 292 | Polk | 41 36 07 N | 093 39 14 W |
| Jewish Cemetery | Cemetery | 283 | Appanoose | 40 44 54 N | 092 52 04 W |
| Jewish Cemetery | Cemetery | 204 | Des Moines | 40 49 23 N | 091 07 53 W |
| Jewish Cemetery | Cemetery | 201 | Muscatine | 41 27 03 N | 091 00 44 W |
| Jim Branch | Stream | | Cass | 41 22 36 N | 094 57 48 W |
| Jim Creek | Stream | | Boone | 41 56 19 N | 094 06 31 W |
| Jim Creek | Stream | | Madison | 41 29 41 N | 094 12 18 W |
| Jim Creek | Stream | | Pottawattamie | 41 25 31 N | 095 21 21 W |
| Jim Ellefson Free Medical Clinic | Hospital | 247 | Polk | 41 36 22 N | 093 33 53 W |
| Jirak Landing Strip | Airport | 361 | Winneshiek | 43 08 42 N | 092 03 13 W |
| JJ Jensen Baseball and Softball Fields | Park | 379 | Shelby | 41 38 55 N | 095 19 14 W |
| Joachim Prairie | Park | 366 | Chickasaw | 43 12 00 N | 092 23 41 W |
| Joachim Woods Wildlife Area | Park | 363 | Howard | 43 13 10 N | 092 26 11 W |
| Jobes Post Office (historical) | Post Office | 452 | Guthrie | 41 35 25 N | 094 42 01 W |
| Joe Day Lake | Lake | 178 | Jackson | 42 05 35 N | 090 11 11 W |
| Joe Hoye Park | Park | 382 | Emmet | 43 24 33 N | 094 50 32 W |
| Joe Reasoner Dam | Dam | 329 | Humboldt | 42 43 37 N | 094 13 45 W |
| Joe Sheldon County Park | Park | 342 | Humboldt | 42 43 42 N | 094 15 18 W |
| Johanningmeier Cemetery | Cemetery | 311 | Clayton | 42 55 40 N | 091 27 31 W |
| John Adams Middle School | School | 329 | Cerro Gordo | 43 09 05 N | 093 09 59 W |
| John Box Grounds Cemetery | Cemetery | 216 | Lee | 40 39 45 N | 091 19 11 W |
| John Brown Park | Park | 329 | Humboldt | 42 43 06 N | 094 12 55 W |
| John C Clegg Library | Building | 254 | Linn | 42 12 14 N | 091 31 27 W |
| John Cemetery | Cemetery | 281 | Davis | 40 44 05 N | 092 37 00 W |
| John Cline School | School | 262 | Winneshiek | 43 18 19 N | 091 47 09 W |
| John Colloton Pavilion | Building | 219 | Johnson | 41 39 36 N | 091 32 51 W |
| John Crystal Center | Building | 310 | Poweshiek | 41 44 48 N | 092 43 23 W |
| John Deere Dubuque Works Airport | Airport | 256 | Dubuque | 42 34 22 N | 090 42 33 W |
| John Duncan Park | Park | 174 | Muscatine | 41 24 57 N | 091 04 47 W |
| John F Kennedy High School | School | 255 | Linn | 42 01 28 N | 091 40 50 W |
| John F Kennedy School | School | 214 | Scott | 41 33 46 N | 090 35 51 W |
| John Glenn School | School | 229 | Scott | 41 41 24 N | 090 40 38 W |
| John Hans Stauffer Honor House | Building | 267 | Marion | 41 24 12 N | 092 55 09 W |
| John Helmuth Cemetery | Cemetery | 220 | Johnson | 41 33 40 N | 091 41 01 W |
| John James Audubon Statue | Park | 414 | Audubon | 41 43 17 N | 094 55 50 W |
| John K and Luise Hanson Fieldhouse | Building | 390 | Winnebago | 43 15 47 N | 093 38 24 W |
| John L Lewis Mining and Labor Museum | Building | 275 | Lucas | 41 01 46 N | 093 27 41 W |
| John L Lewis Park | Park | 275 | Lucas | 41 01 46 N | 093 27 41 W |
| John L Lewis State Historical Marker | Park | 275 | Lucas | 41 01 46 N | 093 27 41 W |
| John Letter Historical Marker | Park | 235 | Clinton | 41 50 06 N | 090 32 12 W |
| John McDonald Hospital Heliport | Airport | 283 | Jones | 42 14 20 N | 091 12 03 W |
| John O'Donnell Stadium | Park | 171 | Scott | 41 31 08 N | 090 34 52 W |
| John Osborn Historical Marker | Park | 254 | Linn | 42 11 50 N | 091 47 30 W |
| John Pappajohn Business Building | Building | 214 | Johnson | 41 39 47 N | 091 32 07 W |
| John Pappajohn Pavilion | Building | 219 | Johnson | 41 39 34 N | 091 32 51 W |
| John Vardy House (historical) | Building | 221 | Linn | 41 58 28 N | 091 39 46 W |
| John W Eckstein Medical Research Building | Building | 217 | Johnson | 41 39 40 N | 091 32 44 W |
| John Wayne Birthplace | Locale | 340 | Madison | 41 19 59 N | 094 00 46 W |
| John XXIII Church | Church | 257 | Linn | 41 56 55 N | 091 46 26 W |
| Johnny Clock Museum | Building | 221 | Jefferson | 40 59 44 N | 091 45 51 W |
| Johnny Creek | Stream | | Louisa | 41 13 24 N | 091 22 46 W |
| Johnny Walnut Seed Conservation Area | Park | 348 | Chickasaw | 43 11 55 N | 092 16 26 W |
| Johns Creek | Stream | | Dubuque | 42 19 07 N | 090 55 23 W |
| Johns Creek | Stream | | Plymouth | 42 35 52 N | 095 58 50 W |
| Johns Creek Cemetery | Cemetery | 299 | Dubuque | 42 22 55 N | 091 02 02 W |
| Johnson (historical) | Populated Place | 262 | Jones | 42 08 57 N | 091 01 59 W |
| Johnson Cemetery | Cemetery | 295 | Appanoose | 40 53 00 N | 093 05 51 W |
| Johnson Cemetery | Cemetery | 282 | Davis | 40 37 47 N | 092 34 38 W |
| Johnson Cemetery | Cemetery | 344 | Decatur | 40 49 28 N | 093 42 53 W |
| Johnson Cemetery | Cemetery | 214 | Des Moines | 40 49 20 N | 091 12 31 W |
| Johnson Cemetery | Cemetery | 334 | Dubuque | 42 27 17 N | 090 52 44 W |
| Johnson Cemetery | Cemetery | 240 | Keokuk | 41 22 57 N | 092 14 56 W |
| Johnson Cemetery | Cemetery | 191 | Lee | 40 33 40 N | 091 39 01 W |
| Johnson County | Civil | 214 | Johnson | 41 40 00 N | 091 32 01 W |
| Johnson County Courthouse | Building | 211 | Johnson | 41 39 22 N | 091 32 06 W |
| Johnson County Fairgrounds | Locale | 198 | Johnson | 41 37 32 N | 091 32 46 W |
| Johnson County Fairgrounds (historical) | Locale | 198 | Johnson | 41 38 12 N | 091 32 24 W |
| Johnson County Home | Building | 226 | Johnson | 41 15 24 N | 091 36 10 W |
| Johnson County Sheriffs Office | Building | 201 | Johnson | 41 39 23 N | 091 32 12 W |
| Johnson Creek | Stream | | Butler | 42 35 44 N | 092 45 45 W |
| Johnson Creek | Stream | | Dallas | 41 31 25 N | 093 50 23 W |
| Johnson Creek | Stream | | O'Brien | 43 02 12 N | 095 43 10 W |
| Johnson Elementary School | School | 401 | Clay | 43 08 46 N | 095 09 23 W |
| Johnson Hienel Access Area | Park | 347 | Cherokee | 42 36 14 N | 095 41 36 W |
| Johnson Island | Island | 161 | Des Moines | 41 00 15 N | 090 57 16 W |
| Johnson Island | Island | 181 | Des Moines | 40 59 55 N | 090 47 47 W |
| Johnson Park | Park | 389 | Crawford | 42 01 56 N | 095 20 31 W |
| Johnson Post Office (historical) | Post Office | 262 | Jones | 42 08 57 N | 091 01 59 W |
| Johnson Prairie | Park | 359 | Calhoun | 42 21 50 N | 094 31 33 W |
| Johnson School | School | 230 | Linn | 41 59 10 N | 091 38 42 W |
| Johnson School | School | 217 | Scott | 41 32 16 N | 090 36 15 W |
| Johnson Town Cemetery | Cemetery | 256 | Jones | 42 08 43 N | 091 02 02 W |
| Johnson Wellness Center | Building | 265 | Polk | 41 37 10 N | 093 36 09 W |
| Johnson Wilderness Area | Park | 484 | Osceola | 43 24 48 N | 095 38 26 W |
| Johnson's Settlement Post Office | Post Office | 362 | Kossuth | 43 08 35 N | 094 15 51 W |
| Johnson/Noel Buckeye Area | Park | 211 | Wapello | 41 02 30 N | 092 11 21 W |
| Johnsons Grove Post Office (historical) | Post Office | 317 | Story | 42 05 30 N | 093 22 21 W |
| Johnsons Port | Locale | 187 | Allamakee | 43 07 54 N | 091 10 50 W |
| Johnsons Slough | Channel | 186 | Clayton | 42 57 21 N | 091 09 46 W |
| Johnsonville Post Office (historical) | Post Office | 429 | Crawford | 42 09 10 N | 095 18 18 W |
| Johnston | Locale | 253 | Polk | 41 40 19 N | 093 41 55 W |
| Johnston | Populated Place | 253 | Polk | 41 40 23 N | 093 41 52 W |
| Johnston Cemetery | Cemetery | 353 | Ringgold | 40 47 37 N | 094 08 50 W |
| Johnston Evangelical Free Church | Church | 293 | Polk | 41 40 25 N | 093 45 06 W |
| Johnston Family Cemetery | Cemetery | 258 | Monroe | 41 04 00 N | 092 41 11 W |
| Johnston Family Practice | Hospital | 252 | Polk | 41 39 50 N | 093 42 06 W |
| Johnston Foot and Ankle Clinic | Hospital | 253 | Polk | 41 39 23 N | 093 41 51 W |
| Johnston High School | School | 253 | Polk | 41 40 26 N | 093 42 21 W |
| Johnston Middle School | School | 253 | Polk | 41 40 26 N | 093 42 03 W |
| Johnston Pediatrics Clinic | Hospital | 253 | Polk | 41 39 23 N | 093 41 51 W |