Annandale-on-Hudson is a hamlet in Dutchess County, New York, United States, in the Hudson Valley in the town of Red Hook, across the Hudson River from Kingston. The town takes its name from an estate donated by John Bard and his wife to Columbia University so that a college could be formed there. Today, Bard College stands on the land that John Bard donated. Bard College houses the only post office for Annandale-on-Hudson's ZIP code, 12504. The land comprising Annandale-on-Hudson, sometimes shortened to just "Annandale", is primarily owned by Bard College, though there are a few private residences, some small businesses, and undeveloped land controlled by the New York State Department of Environmental Conservation.