St. Johnsville is a town in Montgomery County, New York, United States. The population was 2,631 at the 2010 census. Accounts vary as to the naming of St. Johnsville, but most of them state that the town and its village are named after an early surveyor and commissioner, Alexander St. John. Still others credit the naming of St. Johnsville to a former name for the area, St. John’s Church.
According to the United States Census Bureau, the town has a total area of 17.4 square miles (45.0 km²), of which, 16.8 square miles (43.6 km²) of it is land and 0.5 square miles (1.4 km²) of it (3.11%) is water.
The Mohawk River forms the south town line. The north town line is the border of Fulton County, and the west town line is the border of Herkimer County, marked by East Canada Creek.
St. Johnsville is the smallest town in the county (by area).
NY-5 is an east-west highway in the south part of the town. The western terminus of NY-67 is at NY-5, east of St. Johnsville village. The southern terminus of NY-331 is near the northwest part of the town.
As of the census of 2000, there were 2,565 people, 1,043 households, and 658 families residing in the town. The population density was 152.4 people per square mile (58.8/km²). There were 1,170 housing units at an average density of 69.5 per square mile (26.8/km²). The racial makeup of the town was 98.67% White, 0.08% Black or African American, 0.39% Native American, 0.16% Asian, 0.04% Pacific Islander, 0.12% from other races, and 0.55% from two or more races. Hispanic or Latino of any race were 1.36% of the population.
There were 1,043 households out of which 27.8% had children under the age of 18 living with them, 45.7% were married couples living together, 12.0% had a female householder with no husband present, and 36.9% were non-families. 31.5% of all households were made up of individuals and 17.5% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.91.
In the town, the population was spread out with 23.4% under the age of 18, 8.0% from 18 to 24, 24.1% from 25 to 44, 22.4% from 45 to 64, and 22.1% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 91.6 males. For every 100 females age 18 and over, there were 87.8 males.
The median income for a household in the town was $30,719, and the median income for a family was $39,830. Males had a median income of $25,000 versus $21,010 for females. The per capita income for the town was $15,116. About 9.5% of families and 12.4% of the population were below the poverty line, including 20.4% of those under age 18 and 6.5% of those age 65 or over.