Ottumwa
- County:
- Wapello County
- County Seat:
- Yes
- Area (mi²):
- 16.064
- State:
- Iowa
Ottumwa is a city located in Wapello County, Iowa. Ottumwa has a 2026 population of 25,648. It is also the county seat of Wapello County. Ottumwa is currently growing at a rate of 0.83% annually and its population has increased by 0.74% since the most recent census, which recorded a population of 25,459 in 2020.