Missouri Valley
- County:
- Harrison County
- County Seat:
- No
- Area (mi²):
- 3.322
- State:
- Iowa
Missouri Valley is a city located in Harrison County, Iowa. Missouri Valley has a 2026 population of 2,638. Missouri Valley is currently declining at a rate of -0.45% annually and its population has decreased by -1.38% since the most recent census, which recorded a population of 2,675 in 2020.