Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Seibert Park | Park | 290 | Delaware | 42 30 04 N | 091 27 51 W |
| Seigel | Populated Place | 316 | Bremer | 42 50 24 N | 092 21 22 W |
| Seigel Post Office (historical) | Post Office | 316 | Bremer | 42 50 24 N | 092 21 22 W |
| Seights Creek | Stream | | Van Buren | 40 49 16 N | 092 06 18 W |
| Selection | Populated Place | 289 | Monroe | 40 57 50 N | 092 46 60 W |
| Selection (historical) | Locale | 289 | Monroe | 40 57 50 N | 092 47 00 W |
| Selection Post Office (historical) | Post Office | 289 | Monroe | 40 57 50 N | 092 46 60 W |
| Selma | Populated Place | 188 | Van Buren | 40 52 13 N | 092 09 12 W |
| Selma (historical) | Locale | 188 | Van Buren | 40 52 20 N | 092 09 12 W |
| Selma (historical) | Locale | 334 | Wayne | 40 53 42 N | 093 30 09 W |
| Selma Access | Locale | 181 | Davis | 40 53 10 N | 092 12 01 W |
| Selma Post Office | Post Office | 188 | Van Buren | 40 52 20 N | 092 09 12 W |
| Selma Post Office (historical) | Post Office | 334 | Wayne | 40 53 42 N | 093 30 09 W |
| Selma Wildlife Area | Park | 208 | Van Buren | 40 52 32 N | 092 07 41 W |
| Semco School | School | 314 | Marshall | 41 52 39 N | 092 47 06 W |
| Seminole Valley Farm Museum | Building | 225 | Linn | 42 00 20 N | 091 43 31 W |
| Seminole Valley Park | Park | 222 | Linn | 42 00 09 N | 091 43 50 W |
| Seneca | Populated Place | 366 | Kossuth | 43 17 57 N | 094 23 03 W |
| Seneca Access | Locale | 357 | Kossuth | 43 18 48 N | 094 24 28 W |
| Seneca Access Public Hunting Area | Area | 366 | Kossuth | 43 18 51 N | 094 23 53 W |
| Seneca Post Office (historical) | Post Office | 370 | Kossuth | 43 19 55 N | 094 26 01 W |
| Seneca Township Cemetery | Cemetery | 370 | Kossuth | 43 19 11 N | 094 25 07 W |
| Seney | Locale | 378 | Plymouth | 42 51 10 N | 096 07 43 W |
| Seney | Locale | 374 | Plymouth | 42 51 10 N | 096 07 39 W |
| Seney | Populated Place | 378 | Plymouth | 42 51 10 N | 096 07 51 W |
| Seney City Cemetery | Cemetery | 378 | Plymouth | 42 51 31 N | 096 07 33 W |
| Seney Post Office (historical) | Post Office | 378 | Plymouth | 42 51 10 N | 096 07 51 W |
| Seney United Methodist Church | Church | 378 | Plymouth | 42 51 10 N | 096 07 51 W |
| Senior Living Center | Hospital | 374 | Pocahontas | 42 44 31 N | 094 40 41 W |
| Sentral High School | School | 374 | Kossuth | 43 12 41 N | 094 23 14 W |
| Sergeant Bluff | Cliff | 332 | Woodbury | 42 23 60 N | 096 21 01 W |
| Sergeant Bluff | Locale | 333 | Woodbury | 42 24 13 N | 096 21 26 W |
| Sergeant Bluff | Populated Place | 333 | Woodbury | 42 24 14 N | 096 21 31 W |
| Sergeant Bluff - Luton Elementary School | School | 332 | Woodbury | 42 23 56 N | 096 21 34 W |
| Sergeant Bluff - Luton High School | School | 332 | Woodbury | 42 23 40 N | 096 21 12 W |
| Sergeant Bluff - Luton Middle School | School | 332 | Woodbury | 42 23 43 N | 096 21 15 W |
| Sergeant Bluff City Hall | Building | 333 | Woodbury | 42 24 15 N | 096 21 36 W |
| Sergeant Bluff Fire Department | Building | 333 | Woodbury | 42 24 15 N | 096 21 36 W |
| Sergeant Bluff North Bound Rest Area | Locale | 332 | Woodbury | 42 22 31 N | 096 21 11 W |
| Sergeant Bluff Police Department | Building | 334 | Woodbury | 42 24 15 N | 096 21 43 W |
| Sergeant Bluff Post Office | Post Office | 333 | Woodbury | 42 24 13 N | 096 21 34 W |
| Sergeant Bluff South Bound Rist Area | Locale | 333 | Woodbury | 42 22 31 N | 096 21 18 W |
| Sergeant Floyd Monument | Park | 363 | Woodbury | 42 27 46 N | 096 22 40 W |
| Sergeant Floyd Monument State Historical Marker | Park | 333 | Woodbury | 42 22 31 N | 096 21 19 W |
| Sergeant Floyd Monument State Historical Marker | Park | 332 | Woodbury | 42 22 31 N | 096 21 11 W |
| Sergeant Floyd Riverboat Museum and Welcome Center | Locale | 333 | Woodbury | 42 29 29 N | 096 25 08 W |
| Service Chapel Cemetery | Cemetery | 280 | Monroe | 41 05 27 N | 092 48 06 W |
| Sesquicentennial Park | Park | 296 | Warren | 41 21 35 N | 093 33 33 W |
| Seton Catholic Elementary School | School | 319 | Dubuque | 42 26 38 N | 090 55 51 W |
| Seton Catholic School | School | 214 | Wapello | 41 01 10 N | 092 24 35 W |
| Seton Grade School | School | 367 | Kossuth | 43 04 17 N | 094 13 40 W |
| Settlers Canoe Access | Locale | 412 | Sioux | 43 13 40 N | 096 28 51 W |
| Sevanth-Day Adventist Church | Church | 242 | Linn | 42 01 20 N | 091 39 41 W |
| Sevastapol Post Office (historical) | Post Office | 246 | Polk | 41 34 05 N | 093 35 47 W |
| Seven Bridges County Park | Park | 290 | Bremer | 42 39 33 N | 092 09 33 W |
| Seven Hills County Park | Park | 327 | Greene | 41 59 25 N | 094 23 41 W |
| Seven Ponds Park | Park | 216 | Des Moines | 40 58 00 N | 091 08 06 W |
| Seven Revolutionary Soldiers Buried in Des Moines County Historical Museum | Park | 171 | Des Moines | 40 48 43 N | 091 06 05 W |
| Sevenmile Creek | Stream | | Decatur | 40 35 42 N | 093 54 47 W |
| Sevenmile Creek | Stream | | Montgomery | 41 05 02 N | 094 59 45 W |
| Sevenmile Creek | Stream | | Union | 40 57 27 N | 094 01 44 W |
| Seventh Day Adventist Cemetery | Cemetery | 442 | Audubon | 41 37 50 N | 094 58 11 W |
| Seventh Day Adventist Church | Church | 390 | Allamakee | 43 16 12 N | 091 29 05 W |
| Seventh Day Adventist Church | Church | 306 | Appanoose | 40 44 00 N | 092 52 26 W |
| Seventh Day Adventist Church | Church | 421 | Audubon | 41 43 11 N | 094 55 27 W |
| Seventh Day Adventist Church | Church | 281 | Black Hawk | 42 32 30 N | 092 20 41 W |
| Seventh Day Adventist Church | Church | 349 | Boone | 42 03 46 N | 093 52 23 W |
| Seventh Day Adventist Church | Church | 378 | Calhoun | 42 16 05 N | 094 43 47 W |
| Seventh Day Adventist Church | Church | 372 | Cass | 41 24 15 N | 094 59 03 W |
| Seventh Day Adventist Church | Church | 333 | Cerro Gordo | 43 09 36 N | 093 10 51 W |
| Seventh Day Adventist Church | Church | 401 | Clay | 43 08 36 N | 095 08 12 W |
| Seventh Day Adventist Church | Church | 187 | Clinton | 41 50 17 N | 090 11 49 W |
| Seventh Day Adventist Church | Church | 210 | Des Moines | 40 47 54 N | 091 06 51 W |
| Seventh Day Adventist Church | Church | 426 | Dickinson | 43 25 46 N | 095 05 52 W |
| Seventh Day Adventist Church | Church | 314 | Floyd | 43 04 10 N | 092 41 31 W |
| Seventh Day Adventist Church | Church | 234 | Jefferson | 41 00 25 N | 091 57 51 W |
| Seventh Day Adventist Church | Church | 217 | Johnson | 41 39 58 N | 091 33 14 W |
| Seventh Day Adventist Church | Church | 343 | Madison | 41 19 50 N | 094 01 31 W |
| Seventh Day Adventist Church | Church | 320 | Monona | 42 01 30 N | 096 06 08 W |
| Seventh Day Adventist Church | Church | 290 | Monroe | 41 01 15 N | 092 48 31 W |
| Seventh Day Adventist Church | Church | 216 | Muscatine | 41 26 35 N | 091 04 10 W |
| Seventh Day Adventist Church | Church | 289 | Polk | 41 32 55 N | 093 38 55 W |
| Seventh Day Adventist Church | Church | 272 | Polk | 41 34 58 N | 093 42 59 W |
| Seventh Day Adventist Church | Church | 305 | Pottawattamie | 41 15 35 N | 095 48 21 W |
| Seventh Day Adventist Church | Church | 375 | Ringgold | 40 43 10 N | 094 14 21 W |
| Seventh Day Adventist Church | Church | 219 | Scott | 41 32 07 N | 090 35 38 W |
| Seventh Day Adventist Church | Church | 388 | Shelby | 41 38 55 N | 095 19 39 W |
| Seventh Day Adventist Church | Church | 301 | Story | 42 00 36 N | 093 27 07 W |
| Seventh Day Adventist Church | Church | 359 | Taylor | 40 40 24 N | 094 43 18 W |
| Seventh Day Adventist Church | Church | 199 | Wapello | 41 00 50 N | 092 26 19 W |
| Seventh Day Adventist Church | Church | 339 | Webster | 42 31 15 N | 094 11 32 W |
| Seventh Day Adventist Church Cemetery | Cemetery | 270 | Iowa | 41 45 20 N | 092 14 21 W |
| Seventh Day Adventist School | School | 333 | Cerro Gordo | 43 09 35 N | 093 10 51 W |
| Seventh Day Adventist School | School | 213 | Muscatine | 41 25 30 N | 091 04 07 W |
| Seventh Day Church of God | Church | 271 | Linn | 41 58 09 N | 091 37 19 W |
| Seventh-Day Adventist Church | Church | 286 | Marshall | 42 02 39 N | 092 55 22 W |
| Seventy Eight | Locale | 205 | Johnson | 41 32 13 N | 091 33 36 W |
| Seventy Eight Post Office (historical) | Post Office | 205 | Johnson | 41 32 13 N | 091 33 36 W |
| Seventy Six Centre Post Office (historical) | Post Office | 241 | Washington | 41 23 00 N | 091 53 51 W |
| Seventy-Six Townhall | Building | 223 | Muscatine | 41 23 33 N | 091 12 51 W |
| Severance Hall | Building | 269 | Dubuque | 42 29 50 N | 090 41 33 W |
| Severs | Populated Place | 259 | Jasper | 41 39 06 N | 093 12 48 W |
| Severs Creek | Stream | | Jasper | 41 40 27 N | 093 09 29 W |
| Sewal | Locale | 335 | Wayne | 40 38 39 N | 093 15 32 W |
| Sewal | Populated Place | 335 | Wayne | 40 38 39 N | 093 15 32 W |
| Sewal Post Office (historical) | Post Office | 335 | Wayne | 40 38 39 N | 093 15 32 W |
| Sewer Creek | Stream | | Clay | 43 09 12 N | 095 21 04 W |
| Sewer Creek | Stream | | Jasper | 41 36 53 N | 093 04 55 W |
| Sexauer School (historical) | School | 280 | Polk | 41 45 45 N | 093 35 36 W |
| Sexton | Locale | 370 | Kossuth | 43 04 53 N | 094 05 31 W |