Old Brookville is a village located within the Town of Oyster Bay in Nassau County, on the North Shore of Long Island, in New York, United States.

[4] According to the United States Census Bureau, the village has a total area of 4.0 square miles (10 km2), all land.

As of August 2021, the Mayor of Old Brookville is Bernard D. Ryba and the Village Trustees are William Clarke, Frank Galluzzo, Lori Golden, and John Vasilakis.

[3] Old Brookville is primarily located within the boundaries of and is thus served by the North Shore Central School District.

[8] However, some of the eastern side of the village is within the boundaries of and is served by the Locust Valley Central School District.