According to the United States Census Bureau, the town has a total area of 46.7 square miles (121 km2), of which 46.3 square miles (120 km2) is land and 0.4 square miles (1.0 km2) (0.79%) is water.
As of the census[6] of 2000, there were 5,420 people, 2,005 households, and 1,337 families residing in the town. The population density was 117.0 inhabitants 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.
West Shelby – In the southwest corner of the town by the Iroquois Refuge.
Shelby Center – Joseph Ellicott, an agent of the Holland Land Company, purchased land near here in order to use a waterfall on Oak Orchard River. This hamlet is south of Medina on NY-63.
Shelby Basin – A former wide part of the Erie Canal, where barges could turn is west of Medina.