Effingham
- County:
- Atchison County
- County Seat:
- No
- Area (mi²):
- 0.619
- State:
- Kansas
Effingham is a city located in Atchison County, Kansas. Effingham has a 2026 population of 487. Effingham is currently growing at a rate of 0.21% annually but its population has decreased by -1.02% since the most recent census, which recorded a population of 492 in 2020.