Chelsea is a neighborhood on the West Side of the borough of Manhattan in New York City. The district's boundaries are roughly 14th Street to the south, 30th Street to the north, the western boundary of the Ladies' Mile Historic District – which lies between the Avenue of the Americas (Sixth Avenue) and Seventh Avenue – to the east, and the Hudson River and West Street to the west. To the north of Chelsea is the neighborhood of Hell's Kitchen (also known as "Clinton"), as well as the Hudson Yards; to the northeast is the Garment District; to the east are NoMad and the Flatiron District; to the southwest is the Meatpacking District; and to the southeast is Greenwich Village and the West Village.

Chelsea is divided between Manhattan Community Board 4 and Manhattan Community Board 5. It contains the Chelsea Historic District and its extension, which were designated by the New York City Landmarks Preservation Commission in 1970 and 1981, respectively, and added to the National Register of Historic Places in 1977, expanded in 1982 to include contiguous blocks containing particularly significant examples of period architecture.

The neighborhood is primarily residential, with a mix of tenements, apartment blocks, city housing projects, townhouses, and renovated rowhouses, but its many retail businesses reflect the ethnic and social diversity of the population. The area has a large gay population. Chelsea is also known as the center of the New York art world, with over 200 galleries in the neighborhood.