Millbrook is a village in Dutchess County, New York, United States. Millbrook is located in the Hudson Valley, on the east side of the Hudson River, 90 miles (140 km) north of New York City. Millbrook is near the center of the town of Washington, of which it is a part. In the 2020 census, Millbrook's population was 1,455. It is often referred to as a low-key version of the Hamptons, and is one of the most affluent villages in New York.

Dutchess County is a county in the U.S. state of New York. As of the 2020 census, the population was 295,911. The county seat is the city of Poughkeepsie. The county was created in 1683, one of New York's first twelve counties, and later organized in 1713. The county is part of the Hudson Valley region of the state.