Mannsville is a hamlet within the town of Colonie, Albany County, New York, United States.

Albany County eventually foreclosed, auctioning the land off in lots, leading to a boom in new housing in the 1970s.

[1] In 1998, the neighboring city of Watervliet attempted to annex the small hamlet, which at that time consisted of roughly 175 inhabitants.

[3] Mannsville is generally understood to be bordered on the south by NY Route 155; on the north by 15th Street and the Watervliet city line; on the east by Elbow Alley, which runs between Eighth and Ninth Avenues and Watervliet city line; and on the west by railroad tracks.

Since, 1995 residents have complained of frequent flooding due partly to beaver dams on the Kromma Kill and to increased residential construction uphill and upstream from the hamlet.