| Official Name: | St. Martin, Ohio |
| Settlement Type: | Unincorporated community |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Ohio |
| Subdivision Type2: | County |
| Subdivision Name2: | Brown |
| Subdivision Type3: | Township |
| Subdivision Name3: | Perry |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 5.02 |
| Area Land Km2: | 5.02 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 1.94 |
| Area Land Sq Mi: | 1.94 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Total: | 200 |
| Population Density Km2: | 39.86 |
| Population Density Sq Mi: | 103.25 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 971 |
| Coordinates: | 39.2106°N -83.8792°W |
| Blank Name: | FIPS code |
| Blank Info: | 39-69666[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2725568 |
St. Martin is an unincorporated community and former village in Brown County, Ohio, United States. The community is served by the Fayetteville (45118) post office.[3] The population was 200 at the 2020 census.[4] In November 2011, voters chose to unincorporate St. Martin, and it now falls solely under the jurisdiction of Perry Township.[5] [6]
According to the 2010 census, the village had a total area of 1.09sqmi, all land.[7]
As of the census[8] of 2010, there were 129 people, 47 households, and 36 families living in the village. The population density was 118.3PD/sqmi. There were 50 housing units at an average density of 45.9/sqmi. The racial makeup of the village was 99.2% White and 0.8% from two or more races.
There were 47 households, out of which 29.8% had children under the age of 18 living with them, 72.3% were married couples living together, 2.1% had a female householder with no husband present, 2.1% had a male householder with no wife present, and 23.4% were non-families. 14.9% of all households were made up of individuals, and 10.7% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 2.97.
The median age in the village was 49.2 years. 19.4% of residents were under the age of 18; 6.2% were between the ages of 18 and 24; 16.3% were from 25 to 44; 42.7% were from 45 to 64; and 15.5% were 65 years of age or older. The gender makeup of the village was 48.8% male and 51.2% female.
As of the census of 2000, there were 91 people, 32 households, and 28 families living in the village. The population density was 78.3sp=usNaNsp=us. There were 34 housing units at an average density of 29.3sp=usNaNsp=us. The racial makeup of the village was 100.00% White. Hispanic or Latino of any race were 1.10% of the population.
There were 32 households, out of which 40.6% had children under the age of 18 living with them, 81.3% were married couples living together, 6.3% had a female householder with no husband present, and 12.5% were non-families. 12.5% of all households were made up of individuals, and 6.3% had someone living alone who was 65 years of age or older. The average household size was 2.84 and the average family size was 3.11.
In the village the population was spread out, with 28.6% under the age of 18, 6.6% from 18 to 24, 26.4% from 25 to 44, 30.8% from 45 to 64, and 7.7% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 102.2 males. For every 100 females age 18 and over, there were 103.1 males.
The median income for a household in the village was $60,417, and the median income for a family was $60,833. Males had a median income of $33,750 versus $28,125 for females. The per capita income for the village was $18,833. None of the population and none of the families were below the poverty line.