Croghan /ˈkroʊɡən/ is a town in Lewis County, New York, United States. The population was 3,093 at the 2010 census.
According to the United States Census Bureau, the town has a total area of 182.1 square miles (471.5 km²), of which 179.4 square miles (464.7 km²) is land and 2.7 square miles (6.9 km²) (1.46%) is water.
The west town line is partly the border of Jefferson County, and the east town line is the border of Herkimer County.
The Black River defines the west town line. The Indian River flows out from the northwest part of the town. The Beaver River flows through the south part of Croghan.
New York State Route 812 is a north-south highway in the town. NY-812 intersects New York State Route 126 at the south town line. NY-126 intersects east-west highway New York State Route 410 by the west town line.
As of the census of 2000, there were 3,161 people, 1,115 households, and 855 families residing in the town. The population density was 17.6 people per square mile (6.8/km²). There were 1,664 housing units at an average density of 9.3 per square mile (3.6/km²). The racial makeup of the town was 99.24% White, 0.13% Black or African American, 0.06% Native American, 0.06% Asian, 0.22% from other races, and 0.28% from two or more races. Hispanic or Latino of any race were 0.47% of the population.
There were 1,115 households out of which 37.9% had children under the age of 18 living with them, 64.0% were married couples living together, 7.3% had a female householder with no husband present, and 23.3% were non-families. 18.7% of all households were made up of individuals and 9.7% had someone living alone who was 65 years of age or older. The average household size was 2.83 and the average family size was 3.25.
In the town, the population was spread out with 28.7% under the age of 18, 8.4% from 18 to 24, 28.3% from 25 to 44, 22.9% from 45 to 64, and 11.7% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 102.0 males. For every 100 females age 18 and over, there were 100.5 males.
The median income for a household in the town was $34,722, and the median income for a family was $39,267. Males had a median income of $28,712 versus $19,423 for females. The per capita income for the town was $13,408. About 9.0% of families and 12.1% of the population were below the poverty line, including 13.9% of those under age 18 and 15.5% of those age 65 or over.