
Flat Rock
- County:
- Seneca County
- County Seat:
- No
- Area (mi²):
- 0.212
- State:
- Ohio
Flat Rock is a CDP located in Seneca County, Ohio. Flat Rock has a 2025 population of 308. Flat Rock is currently growing at a rate of 1.65% annually and its population has increased by 18.01% since the most recent census, which recorded a population of 261 in 2020.
The average household income in Flat Rock is $47,550 with a poverty rate of 25%. The median age in Flat Rock is 39.7 years: 40.2 years for males, and 39.5 years for females.