Nassau is bordered on the west by the Valatie Kill and Schodack township and is 15 miles east of Albany, New York state's capital city.

The village is near the site of the first settlement of the town, which took place circa 1760.

[3] According to the United States Census Bureau, the village has a total area of 0.7 square mile (1.8 km2), all land.

There were 529 housing units at an average density of 776.9 per square mile (300.0/km2).

29.0% of all households were made up of individuals, and 12.4% had someone living alone who was 65 years of age or older.