
St Martin
- County:
- Brown County
- County Seat:
- No
- Area (mi²):
- 1.937
- State:
- Ohio
St. Martin is a CDP located in Brown County, Ohio. St. Martin has a 2025 population of 169. St. Martin is currently growing at a rate of 6.96% annually and its population has increased by 3.05% since the most recent census, which recorded a population of 164 in 2020.
The average household income in St. Martin is $83,741 with a poverty rate of 7.09%. The median age in St. Martin is 55.4 years: 60.9 years for males, and 49.7 years for females.