Newcomb is a town in Essex County, New York, United States. The population was 436 at the 2010 census.
According to the United States Census Bureau, the town has a total area of 233.2 square miles (603.9 km), of which 226.3 square miles (586.0 km) is land and 6.9 square miles (17.9 km), or 2.96%, is water. The Hudson River officially starts at Henderson Lake in the northeast part of town and flows southward through the center of town.
The northern part of the west town line is the border of Hamilton County. The western part of the north town line is the border of Franklin County.
New York State Route 28N, an east-west road, is a major highway in Newcomb.
As of the census of 2000, there were 481 people, 211 households, and 140 families residing in the town. The population density was 2.1 people per square mile (0.8/km²). There were 655 housing units at an average density of 2.9 per square mile (1.1/km²). The racial makeup of the town was 95.22% White, 0.62% Native American, 0.62% from other races, and 3.53% from two or more races. Hispanic or Latino of any race were 0.42% of the population.
There were 211 households out of which 19.9% had children under the age of 18 living with them, 60.2% were married couples living together, 4.3% had a female householder with no husband present, and 33.2% were non-families. 30.3% of all households were made up of individuals and 16.1% had someone living alone who was 65 years of age or older. The average household size was 2.26 and the average family size was 2.81.
In the town, the population was spread out with 19.5% under the age of 18, 3.7% from 18 to 24, 18.9% from 25 to 44, 31.0% from 45 to 64, and 26.8% who were 65 years of age or older. The median age was 51 years. For every 100 females, there were 96.3 males. For every 100 females age 18 and over, there were 93.5 males.
The median income for a household in the town was $32,639, and the median income for a family was $41,875. Males had a median income of $35,750 versus $28,750 for females. The per capita income for the town was $17,043. About 5.8% of families and 9.1% of the population were below the poverty line, including 19.5% of those under age 18 and 3.5% of those age 65 or over.