Dutchess County is a county located in the U.S. state of New York. It sits in the state's Mid-Hudson Region of the Hudson Valley. As of 2000, the population was 280,150. It is part of the New York Metropolitan Area. The county seat is Poughkeepsie. The county was named in honor of Mary of Modena, Duchess of York, second wife of the future King James II. Somehow, a "t" got added to the county name. This was probably a misunderstanding due to the large number of Dutch immigrants in upstate New York at the time, coupled with the looseness of spelling in 17th-century English.

Dutchess County is located in eastern New York State, between the Hudson River on its west and the New York-Connecticut border on its east, about halfway between the cities of Albany and New York. It contains two cities: Beacon and Poughkeepsie.