Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Speak the Word Church | Church | 295 | Dallas | 41 36 15 N | 093 58 51 W |
| Spearman Branch | Stream | | Henry | 40 55 04 N | 091 32 28 W |
| Spears Cemetery | Cemetery | 361 | Harrison | 41 30 35 N | 095 34 53 W |
| Spechts Ferry | Locale | 185 | Dubuque | 42 38 30 N | 090 44 00 W |
| Spechts Ferry Post Office (historical) | Post Office | 185 | Dubuque | 42 38 30 N | 090 44 00 W |
| Spectra Health Care | Hospital | 418 | Buena Vista | 42 41 18 N | 095 10 13 W |
| Spedding Hall | Building | 290 | Story | 42 01 47 N | 093 38 54 W |
| Speier Park | Park | 438 | Dickinson | 43 22 52 N | 095 08 13 W |
| Spence Cemetery | Cemetery | 241 | Davis | 40 53 30 N | 092 22 36 W |
| Spence Laboratories of Psychology | Building | 207 | Johnson | 41 39 42 N | 091 31 53 W |
| Spencer | Locale | 401 | Clay | 43 08 40 N | 095 08 41 W |
| Spencer | Populated Place | 400 | Clay | 43 08 29 N | 095 08 40 W |
| Spencer Beach | Beach | 426 | Dickinson | 43 22 10 N | 095 09 40 W |
| Spencer Campground | Locale | 401 | Clay | 43 07 60 N | 095 08 21 W |
| Spencer Cemetery | Cemetery | 284 | Tama | 42 15 35 N | 092 20 04 W |
| Spencer Cemetery | Cemetery | 223 | Van Buren | 40 52 45 N | 091 48 04 W |
| Spencer Cemetery (historical) | Cemetery | 274 | Bremer | 42 42 30 N | 092 26 46 W |
| Spencer Chiropractic Clinic | Hospital | 401 | Clay | 43 07 42 N | 095 08 57 W |
| Spencer Country Club | Locale | 404 | Clay | 43 09 18 N | 095 10 31 W |
| Spencer Creek | Stream | | Scott | 41 34 10 N | 090 25 06 W |
| Spencer Dental Arts Center | Hospital | 405 | Clay | 43 09 18 N | 095 09 48 W |
| Spencer Family Dental Center | Hospital | 400 | Clay | 43 08 33 N | 095 08 33 W |
| Spencer Fire Department | Building | 398 | Clay | 43 08 17 N | 095 08 39 W |
| Spencer Foot and Ankle Clinic | Hospital | 345 | Clarke | 41 01 50 N | 093 45 51 W |
| Spencer Foot and Ankle Clinic | Hospital | 331 | Wayne | 40 45 15 N | 093 18 41 W |
| Spencer High School | School | 401 | Clay | 43 08 27 N | 095 08 01 W |
| Spencer Memorial Chapel | Church | 253 | Mahaska | 41 18 30 N | 092 38 47 W |
| Spencer Middle School | School | 400 | Clay | 43 08 28 N | 095 08 34 W |
| Spencer Municipal Airport | Airport | 407 | Clay | 43 09 52 N | 095 12 07 W |
| Spencer Municipal Golf Course | Locale | 404 | Clay | 43 07 20 N | 095 08 51 W |
| Spencer Municipal Hospital | Hospital | 402 | Clay | 43 08 58 N | 095 08 35 W |
| Spencer Municipal Hospital Heliport | Airport | 402 | Clay | 43 09 02 N | 095 08 32 W |
| Spencer Police Department | Building | 401 | Clay | 43 08 31 N | 095 08 47 W |
| Spencer Post Office | Post Office | 402 | Clay | 43 09 24 N | 095 08 41 W |
| Spencer Public Library | Building | 400 | Clay | 43 08 27 N | 095 08 38 W |
| Spencer Recreation Trail | Trail | 400 | Clay | 43 09 08 N | 095 11 13 W |
| Spencer School | School | 286 | Monroe | 41 02 57 N | 092 50 35 W |
| Spencer School | School | 377 | Pottawattamie | 41 26 01 N | 095 42 28 W |
| Spencers Grove | Populated Place | 296 | Benton | 42 17 04 N | 091 52 09 W |
| Spencers Grove Cemetery | Cemetery | 290 | Benton | 42 17 04 N | 091 51 55 W |
| Spencers Grove Post Office (historical) | Post Office | 284 | Benton | 42 17 06 N | 091 51 51 W |
| Sperati Guest House | Building | 286 | Winneshiek | 43 18 38 N | 091 48 06 W |
| Sperry | Populated Place | 229 | Des Moines | 40 57 25 N | 091 09 24 W |
| Sperry (historical) | Locale | 229 | Des Moines | 40 57 28 N | 091 09 03 W |
| Sperry Elevator | Locale | 236 | Des Moines | 41 00 30 N | 091 09 55 W |
| Sperry Post Office | Post Office | 229 | Des Moines | 40 57 25 N | 091 09 24 W |
| Spicer-Spooner Cemetery | Cemetery | 266 | Iowa | 41 45 40 N | 091 51 01 W |
| Spillers Cemetery | Cemetery | 294 | Dallas | 41 34 00 N | 094 13 46 W |
| Spillville | Populated Place | 326 | Winneshiek | 43 12 18 N | 091 57 04 W |
| Spillville Post Office | Post Office | 326 | Winneshiek | 43 12 18 N | 091 57 04 W |
| Spillville Public Library | Building | 326 | Winneshiek | 43 12 18 N | 091 57 04 W |
| Spine Injury and Pain Center | Hospital | 442 | Dickinson | 43 25 19 N | 095 06 49 W |
| Spires Lake | Lake | 227 | Marion | 41 28 44 N | 093 18 18 W |
| Spirit Lake | Lake | 427 | Dickinson | 43 28 38 N | 095 05 53 W |
| Spirit Lake | Locale | 445 | Dickinson | 43 25 26 N | 095 06 36 W |
| Spirit Lake | Populated Place | 449 | Dickinson | 43 25 20 N | 095 06 08 W |
| Spirit Lake Baptist Church | Church | 449 | Dickinson | 43 25 17 N | 095 06 14 W |
| Spirit Lake Chiropractic Clinic | Hospital | 444 | Dickinson | 43 25 24 N | 095 05 57 W |
| Spirit Lake Elementary School | School | 451 | Dickinson | 43 24 56 N | 095 06 05 W |
| Spirit Lake High School | School | 426 | Dickinson | 43 26 05 N | 095 06 05 W |
| Spirit Lake High School | School | 452 | Dickinson | 43 24 57 N | 095 06 05 W |
| Spirit Lake Massacre Monument | Park | 433 | Dickinson | 43 21 56 N | 095 08 26 W |
| Spirit Lake Medical Center | Hospital | 444 | Dickinson | 43 25 04 N | 095 07 28 W |
| Spirit Lake Middle School | School | 447 | Dickinson | 43 24 56 N | 095 05 51 W |
| Spirit Lake Municipal Airport | Airport | 432 | Dickinson | 43 23 15 N | 095 08 21 W |
| Spirit Lake Police Department | Building | 448 | Dickinson | 43 25 20 N | 095 06 06 W |
| Spirit Lake Post Office | Post Office | 443 | Dickinson | 43 25 29 N | 095 06 07 W |
| Spirit Lake Public Library | Building | 443 | Dickinson | 43 25 29 N | 095 06 06 W |
| Spirit Lake State Game Management Area | Park | 427 | Dickinson | 43 28 38 N | 095 05 37 W |
| Spirit Lake United Methodist Church | Church | 446 | Dickinson | 43 25 20 N | 095 06 01 W |
| Spirit of God Baptist Church | Church | 245 | Scott | 41 31 01 N | 090 47 02 W |
| Spirit of Siouxland Statue | Park | 335 | Woodbury | 42 29 24 N | 096 24 44 W |
| Spirit of the Dove Church | Church | 342 | Cerro Gordo | 43 09 54 N | 093 12 08 W |
| Spiritualist Harmony Church | Church | 178 | Scott | 41 31 35 N | 090 35 47 W |
| Spitznogle Lake | Lake | 168 | Louisa | 41 07 16 N | 091 05 59 W |
| Split Rock County Park | Park | 327 | Chickasaw | 42 54 37 N | 092 14 11 W |
| Split Rock Lake | Reservoir | 323 | Chickasaw | 42 54 36 N | 092 14 25 W |
| Split Rock Lake Dam | Dam | 323 | Chickasaw | 42 54 36 N | 092 14 25 W |
| Spook Cave and Campground | Locale | 290 | Clayton | 43 02 00 N | 091 18 30 W |
| Spooner Ditch | Canal | 309 | Harrison | 41 41 48 N | 096 00 06 W |
| Sport Hill Country Club | Locale | 238 | Iowa | 41 39 18 N | 092 00 51 W |
| Sports Medicine Center | Hospital | 268 | Polk | 41 38 40 N | 093 41 49 W |
| Sports Rehab and Phusical Therapy Center | Hospital | 436 | Buena Vista | 42 38 41 N | 095 12 14 W |
| Sportsman County Park | Park | 369 | Palo Alto | 43 07 32 N | 094 32 55 W |
| Sportsman Lake | Reservoir | 273 | Tama | 42 00 31 N | 092 40 57 W |
| Sportsman Park | Park | 327 | Wright | 42 37 46 N | 093 55 41 W |
| Sportsman Park Racetrack | Locale | 197 | Lee | 40 24 33 N | 091 26 01 W |
| Sportsmans Park | Park | 284 | Butler | 42 47 12 N | 092 40 51 W |
| Sportsmans Park | Park | 307 | Floyd | 43 04 39 N | 092 40 37 W |
| Sportsmans Park | Park | 295 | Page | 40 46 20 N | 095 22 29 W |
| Sportsmens Park | Park | 287 | Bremer | 42 50 51 N | 092 32 14 W |
| Sportsmens Park | Park | 309 | Dallas | 41 50 50 N | 094 12 36 W |
| Spotts Field | Airport | 347 | Cerro Gordo | 43 08 15 N | 093 04 06 W |
| Spragueville | Populated Place | 202 | Jackson | 42 04 21 N | 090 26 06 W |
| Spragueville (historical) | Locale | 192 | Jackson | 42 04 20 N | 090 25 40 W |
| Spragueville Post Office | Post Office | 202 | Jackson | 42 04 21 N | 090 26 06 W |
| Spring Branch | Stream | | Carroll | 41 59 22 N | 094 46 28 W |
| Spring Branch | Stream | | Chickasaw | 42 59 47 N | 092 22 16 W |
| Spring Branch | Stream | | Clayton | 42 48 37 N | 091 19 58 W |
| Spring Branch | Stream | | Delaware | 42 26 35 N | 091 24 40 W |
| Spring Branch | Stream | | Fremont | 40 42 45 N | 095 34 35 W |
| Spring Branch | Stream | | Guthrie | 41 35 10 N | 094 23 48 W |
| Spring Branch | Stream | | Jackson | 42 12 51 N | 090 45 03 W |
| Spring Branch | Stream | | Keokuk | 41 09 27 N | 092 23 02 W |
| Spring Branch Cemetery | Cemetery | 298 | Delaware | 42 28 10 N | 091 24 10 W |
| Spring Branch Church | Church | 340 | Wayne | 40 43 30 N | 093 30 31 W |
| Spring Branch Creek | Stream | | Allamakee | 43 12 18 N | 091 09 20 W |
| Spring Branch Post Office (historical) | Post Office | 310 | Delaware | 42 28 00 N | 091 24 31 W |
| Spring Cemetery | Cemetery | 375 | Cherokee | 42 51 01 N | 095 29 27 W |
| Spring Creek | Stream | | Appanoose | 40 35 57 N | 092 43 08 W |