Chelsea is a neighborhood on the West Side of the borough of Manhattan in New York City. The district's boundaries are roughly 14th Streetto the south, the Hudson River and West Street to the west, and Sixth Avenue to the east, with its northern boundary variously described as near the upper 20s or 34th Street, the next major crosstown street to the north. 

To the northwest of Chelsea is the neighborhood of Hell's Kitchen, as well as Hudson Yards; to the northeast are the Garment District and the remainder of Midtown South; to the east are NoMadand the Flatiron District; to the southwest is the Meatpacking District; and to the south and southeast are the West Village and the remainder of Greenwich Village.

 Chelsea is named after the Royal Hospital Chelsea in London, England.

Chelsea contains the Chelsea Historic District and its extension, which were designated by the New York City Landmarks Preservation Commission in 1970 and 1981 respectively. The district was added to the National Register of Historic Places in 1977, and 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 LGBTQ population. Chelsea is also known as one of the centers of the city's art world, with over 200 galleries in the neighborhood. As of 2015, due to the area's gentrification, there is a widening income gap between the wealthy living in luxury buildings and the poor living in housing projects, who are, at times, across the street from each other. 

The neighborhood is served by the M7, M10, M11, M12, M14 SBS and M23 SBS New York City Bus routes. New York City Subway routes include the 1, ​2, and ​3 services on Seventh Avenue, the A, ​C, and ​E services on Eighth Avenue, and the F, , and ​M services on Sixth Avenue.^[88] The 34th Street – Hudson Yards station on the 7 and <7>​ trains opened in September 2015 with its main entrance in Chelsea