The Incorporated Village of Old Brookville is a village located within the Town of Oyster Bay in Nassau County, New York. As of the United States 2010 Census, the village population was 2,134.
Old Brookville is located at 40°49′38″N 73°36′7″W / 40.82722°N 73.60194°W / 40.82722; -73.60194 (40.827303, -73.601855).
According to the United States Census Bureau, the village has a total area of 4.0 square miles (10 km), all of it land.
As of the census of 2000, there were 2,167 people, 722 households, and 618 families residing in the village. The population density was 545.2 people per square mile (210.8/km²). There were 760 housing units at an average density of 191.2 per square mile (73.9/km²). The racial makeup of the village was 89.20% White, 1.43% African American, 7.34% Asian, 0.55% from other races, and 1.48% from two or more races. Hispanic or Latino of any race were 2.03% of the population.
There were 722 households out of which 36.3% had children under the age of 18 living with them, 76.6% were married couples living together, 7.3% had a female householder with no husband present, and 14.4% were non-families. 11.2% of all households were made up of individuals and 6.0% had someone living alone who was 65 years of age or older. The average household size was 3.00 and the average family size was 3.22.
In the village, the population was spread out with 25.4% under the age of 18, 5.5% from 18 to 24, 23.1% from 25 to 44, 30.5% from 45 to 64, and 15.6% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 97.7 males. For every 100 females age 18 and over, there were 91.8 males.
The median income for a household in the village was $233,192, and the median income for a family was $255,731. Males had a median income of $108,562 versus $82,625 for females. The per capita income for the village was $98,874. About 0.3% of families and 0.4% of the population were below the poverty line, including 0.2% of those under age 18 and 0.7% of those age 65 or over.