
Lancaster
- County:
- Fairfield County
- County Seat:
- Yes
- Area (mi²):
- 19.044
- State:
- Ohio
Lancaster is a city located in Fairfield County, Ohio. Lancaster has a 2025 population of 41,946. It is also the county seat of Fairfield County. Lancaster is currently growing at a rate of 0.63% annually and its population has increased by 3.22% since the most recent census, which recorded a population of 40,636 in 2020.
The average household income in Lancaster is $74,386 with a poverty rate of 14.84%. The median age in Lancaster is 36.9 years: 36.3 years for males, and 37.4 years for females.