
Seneca
- County:
- Newton County
- County Seat:
- No
- Area (mi²):
- 2.559
- State:
- Missouri
Seneca is a city located in Newton County, Missouri. Seneca has a 2025 population of 2,330. Seneca is currently growing at a rate of 0.82% annually and its population has increased by 4.16% since the most recent census, which recorded a population of 2,237 in 2020.
The average household income in Seneca is $59,083 with a poverty rate of 19.08%. The median age in Seneca is 35.7 years: 31.6 years for males, and 40.5 years for females.