Shelby is a town in Orleans County, New York, United States. The population was 5,319 at the 2010 census.
According to the United States Census Bureau, the town has a total area of 46.7 square miles (121 km), of which 46.3 square miles (120 km) is land and 0.4 square miles (1.0 km) (0.79%) is water.
The west town line is shared with the Town of Royalton in Niagara County, and the south town line is shared by the Town of Alabama in Genesee County.
As of the census of 2000, there were 5,420 people, 2,005 households, and 1,337 families residing in the town. The population density was 117.0 people per square mile (45.2/km²). There were 2,133 housing units at an average density of 46.0 per square mile (17.8/km²). The racial makeup of the town was 89.70% White, 7.01% African American, 0.44% Native American, 0.35% Asian, 0.04% Pacific Islander, 1.16% from other races, and 1.29% from two or more races. Hispanic or Latino of any race were 3.28% of the population.
There were 2,005 households out of which 31.4% had children under the age of 18 living with them, 51.0% were married couples living together, 11.3% had a female householder with no husband present, and 33.3% were non-families. 28.6% of all households were made up of individuals and 15.8% had someone living alone who was 65 years of age or older. The average household size was 2.52 and the average family size was 3.09.
In the town, the population was spread out with 26.5% under the age of 18, 8.7% from 18 to 24, 26.2% from 25 to 44, 20.5% from 45 to 64, and 18.1% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 92.1 males. For every 100 females age 18 and over, there were 87.6 males.
The median income for a household in the town was $34,091, and the median income for a family was $40,972. Males had a median income of $32,087 versus $21,299 for females. The per capita income for the town was $17,154. About 8.6% of families and 13.7% of the population were below the poverty line, including 16.4% of those under age 18 and 3.3% of those age 65 or over.