Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Gravel Dale Siding (historical) | Locale | 301 | Greene | 41 59 15 N | 094 21 21 W |
| Gravel Pit | Populated Place | 310 | Greene | 42 04 13 N | 094 17 29 W |
| Graves School | School | 307 | Lucas | 41 08 46 N | 093 18 17 W |
| Graveyard Point | Cape | 210 | Washington | 41 25 37 N | 091 29 10 W |
| Gravity | Populated Place | 366 | Taylor | 40 45 38 N | 094 44 37 W |
| Gravity (historical) | Locale | 351 | Taylor | 40 45 25 N | 094 44 26 W |
| Gravity Cemetery | Cemetery | 380 | Taylor | 40 46 00 N | 094 44 31 W |
| Gravity Christian Church | Church | 366 | Taylor | 40 45 38 N | 094 44 37 W |
| Gravity Church of the Nazarene | Church | 366 | Taylor | 40 45 38 N | 094 44 37 W |
| Gravity Post Office (historical) | Post Office | 386 | Taylor | 40 45 57 N | 094 45 29 W |
| Gray | Populated Place | 416 | Audubon | 41 50 22 N | 094 58 59 W |
| Gray (historical) | Locale | 414 | Audubon | 41 50 20 N | 094 59 01 W |
| Gray Cemetery | Cemetery | 441 | Audubon | 41 50 29 N | 094 59 42 W |
| Gray Cemetery | Cemetery | 230 | Jefferson | 41 04 20 N | 092 09 11 W |
| Gray Creek | Stream | | Cherokee | 42 48 03 N | 095 33 20 W |
| Gray Eagle Wildlife Reserve | Park | 192 | Wapello | 40 59 45 N | 092 23 36 W |
| Gray Hall | Building | 294 | Polk | 41 44 10 N | 093 37 32 W |
| Gray Post Office | Post Office | 416 | Audubon | 41 50 22 N | 094 58 59 W |
| Gray's Ford Cemetery | Cemetery | 215 | Cedar | 41 37 20 N | 091 13 21 W |
| Gray's Landing | Locale | 167 | Lee | 40 47 25 N | 091 21 41 W |
| Gray's Landing Wildlife Area | Park | 342 | Monona | 42 05 47 N | 095 52 18 W |
| Graybill Building | Building | 344 | Decatur | 40 37 01 N | 093 55 30 W |
| Graybill Cemetery | Cemetery | 372 | Harrison | 41 30 33 N | 095 34 50 W |
| Graybill Cemetery | Cemetery | 348 | Pottawattamie | 41 15 10 N | 095 46 31 W |
| Graybill Creek | Stream | | Pottawattamie | 41 10 07 N | 095 23 10 W |
| Grays Creek | Stream | | Monroe | 41 09 36 N | 092 39 27 W |
| Grays Creek School | School | 270 | Monroe | 41 05 47 N | 092 49 46 W |
| Grays Lake | Lake | 238 | Polk | 41 34 12 N | 093 38 18 W |
| Grays Lake Park | Park | 241 | Polk | 41 34 21 N | 093 38 16 W |
| Great Commission Church | Church | 306 | Marshall | 42 02 45 N | 092 57 41 W |
| Great Lakes Dental Center | Hospital | 438 | Dickinson | 43 25 23 N | 095 07 39 W |
| Great Lakes Mall | Locale | 442 | Dickinson | 43 25 19 N | 095 06 49 W |
| Great Oak Post Office (historical) | Post Office | 372 | Palo Alto | 43 05 10 N | 094 43 01 W |
| Great Oak Townhall | Building | 381 | Palo Alto | 43 02 20 N | 094 44 17 W |
| Great Oaks | Populated Place | 207 | Scott | 41 35 39 N | 090 25 17 W |
| Great River Care Center | Hospital | 225 | Clayton | 43 01 13 N | 091 11 35 W |
| Great River Christian School | School | 188 | Des Moines | 40 48 45 N | 091 06 12 W |
| Great River Eye Care | Hospital | 215 | Des Moines | 40 48 40 N | 091 10 16 W |
| Great River Medical Center | Hospital | 214 | Des Moines | 40 48 38 N | 091 10 16 W |
| Great River Road Trail | Trail | 330 | Clayton | 42 54 15 N | 091 10 00 W |
| Great River Womens Health Center | Hospital | 214 | Des Moines | 40 48 38 N | 091 10 16 W |
| Great Western Trail | Trail | 261 | Clarke | 41 28 00 N | 093 47 19 W |
| Greater Community Hospital | Hospital | 396 | Union | 41 04 12 N | 094 23 03 W |
| Greater Community Hospital Heliport | Airport | 380 | Union | 41 04 20 N | 094 23 40 W |
| Greater Community Hospital Medical Center | Hospital | 396 | Union | 41 04 12 N | 094 23 03 W |
| Greater Des Moines Baptist Church | Church | 274 | Polk | 41 36 05 N | 093 42 32 W |
| Greater Des Moines Baptist Church | Church | 278 | Polk | 41 36 02 N | 093 42 26 W |
| Greater Faith Baptist Church | Church | 220 | Scott | 41 34 26 N | 090 36 35 W |
| Greater Hope Missionary Baptist Church | Church | 213 | Des Moines | 40 47 42 N | 091 06 43 W |
| Greater Love Church of God | Church | 249 | Polk | 41 36 19 N | 093 35 10 W |
| Greater Ottumwa Park | Park | 194 | Wapello | 41 00 40 N | 092 25 26 W |
| Greater Shenandoah Historical Museum | Building | 299 | Page | 40 45 58 N | 095 22 12 W |
| Greek Orthodox Church | Church | 236 | Linn | 41 58 54 N | 091 39 56 W |
| Greek Orthodox Church | Church | 295 | Polk | 41 35 53 N | 093 40 02 W |
| Greek Orthodox Church of the Transfiguration | Church | 346 | Cerro Gordo | 43 08 60 N | 093 13 18 W |
| Greeley | Populated Place | 351 | Delaware | 42 35 09 N | 091 20 30 W |
| Greeley (historical) | Locale | 348 | Delaware | 42 35 02 N | 091 20 33 W |
| Greeley City Hall | Building | 351 | Delaware | 42 35 09 N | 091 20 30 W |
| Greeley Post Office | Post Office | 351 | Delaware | 42 35 09 N | 091 20 30 W |
| Greeley United Methodist Church | Church | 351 | Delaware | 42 35 09 N | 091 20 30 W |
| Green Acres | Populated Place | 219 | Scott | 41 34 12 N | 090 36 36 W |
| Green Acres Country Club | Locale | 213 | Lee | 40 38 48 N | 091 34 16 W |
| Green Acres Mobile Home Park | Populated Place | 168 | Des Moines | 40 51 10 N | 091 06 29 W |
| Green Acres Park | Park | 220 | Scott | 41 34 29 N | 090 36 32 W |
| Green Acres School (historical) | School | 220 | Scott | 41 34 26 N | 090 36 35 W |
| Green Bay (historical) | Populated Place | 349 | Clarke | 40 54 55 N | 093 46 28 W |
| Green Bay Access | Locale | 158 | Lee | 40 39 08 N | 091 10 54 W |
| Green Bay Bottoms | Flat | 231 | Lee | 41 40 57 N | 091 12 12 W |
| Green Bay Cemetery | Cemetery | 348 | Clarke | 40 55 17 N | 093 46 35 W |
| Green Bay Cemetery | Cemetery | 336 | Decatur | 40 49 35 N | 093 31 44 W |
| Green Bayou | Gut | 155 | Lee | 40 39 24 N | 091 12 23 W |
| Green Brier | Populated Place | 333 | Greene | 41 55 19 N | 094 25 07 W |
| Green Castle | Populated Place | 280 | Jasper | 41 44 46 N | 093 15 42 W |
| Green Castle (historical) | Populated Place | 218 | Johnson | 41 46 28 N | 091 39 59 W |
| Green Castle Airport | Airport | 232 | Johnson | 41 45 18 N | 091 43 40 W |
| Green Castle Recreation Area | Park | 296 | Marshall | 41 55 45 N | 092 51 31 W |
| Green Cemetery | Cemetery | 291 | Clarke | 41 08 30 N | 093 43 31 W |
| Green Cemetery | Cemetery | 304 | Jasper | 41 50 30 N | 092 48 01 W |
| Green Cemetery (historical) | Cemetery | 340 | Dubuque | 42 24 30 N | 090 36 20 W |
| Green Center | Populated Place | 240 | Iowa | 41 32 25 N | 091 53 12 W |
| Green Center Cemetery | Cemetery | 291 | Jones | 42 01 12 N | 091 13 46 W |
| Green Center Post Office (historical) | Post Office | 240 | Iowa | 41 32 25 N | 091 53 12 W |
| Green Creek | Stream | | Henry | 41 01 30 N | 091 39 30 W |
| Green Glade Cemetery | Cemetery | 171 | Van Buren | 40 37 50 N | 091 44 04 W |
| Green Hill Cemetery | Cemetery | 356 | Clayton | 42 40 26 N | 091 25 16 W |
| Green Hill Post Office (historical) | Post Office | 321 | Delaware | 42 23 10 N | 091 21 01 W |
| Green Hills Health Center | Hospital | 298 | Story | 42 00 08 N | 093 39 01 W |
| Green Hollow Wildlife Management Area | Park | 324 | Fremont | 40 51 10 N | 095 44 31 W |
| Green Island | Locale | 186 | Jackson | 42 09 13 N | 090 19 19 W |
| Green Island | Populated Place | 186 | Jackson | 42 09 13 N | 090 19 19 W |
| Green Island Post Office | Post Office | 186 | Jackson | 42 09 13 N | 090 19 19 W |
| Green Lawn Cemetery | Cemetery | 373 | Union | 41 02 01 N | 094 11 09 W |
| Green Meadows Mobile Home Park | Populated Place | 375 | Cerro Gordo | 43 07 00 N | 093 23 12 W |
| Green Mill Ford Bridge | Bridge | 268 | Bremer | 42 40 22 N | 092 25 46 W |
| Green Mound Cemetery | Cemetery | 217 | Henry | 41 04 11 N | 091 39 56 W |
| Green Mound Church | Church | 220 | Henry | 41 04 15 N | 091 39 53 W |
| Green Mountain | Populated Place | 302 | Marshall | 42 06 06 N | 092 49 14 W |
| Green Mountain (historical) | Locale | 303 | Marshall | 42 06 08 N | 092 49 06 W |
| Green Mountain Cemetery | Cemetery | 299 | Marshall | 42 06 10 N | 092 49 26 W |
| Green Mountain Post Office | Post Office | 302 | Marshall | 42 06 06 N | 092 49 14 W |
| Green Mountain Post Office (historical) | Post Office | 299 | Tama | 42 05 32 N | 092 49 28 W |
| Green Pines Wildlife Area | Park | 297 | Clarke | 41 08 53 N | 093 42 36 W |
| Green Plain Church | Church | 299 | Warren | 41 14 04 N | 093 27 43 W |
| Green Plain School | School | 303 | Warren | 41 14 03 N | 093 27 34 W |
| Green School | School | 337 | Clarke | 41 08 21 N | 093 48 08 W |
| Green Square Park | Park | 223 | Linn | 41 58 41 N | 091 39 49 W |
| Green Townhall | Building | 242 | Wapello | 41 56 44 N | 092 27 59 W |
| Green Valley | Valley | | Monona | 42 03 25 N | 095 54 15 W |
| Green Valley (historical) | Locale | 344 | Decatur | 40 52 43 N | 093 54 18 W |
| Green Valley Cemetery | Cemetery | 363 | Pottawattamie | 41 16 28 N | 095 49 22 W |