| Official Name: | River Sioux, Iowa |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Iowa#USA |
| Pushpin Label: | River Sioux |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Harrison |
| Subdivision Type3: | Township |
| Subdivision Name3: | Little Sioux |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 0.99 |
| Area Land Km2: | 0.99 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 0.38 |
| Area Land Sq Mi: | 0.38 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Total: | 42 |
| Population Density Km2: | 42.61 |
| Population Density Sq Mi: | 110.24 |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Ft: | 1040 |
| Coordinates: | 41.8058°N -96.0464°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 51545[2] |
| Area Code: | 712 |
| Blank Name: | FIPS code |
| Blank Info: | 19-67530 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 460651 |
River Sioux is an unincorporated community and census-designated place in Harrison County, Iowa, United States. As of the 2010 Census the population was 59.[3]
River Sioux was platted in 1868 when the railroad was extended to that point.[4] It was named after the nearby Little Sioux River.[5]
River Sioux is zoned to the West Harrison Community School District.[6]