Madison Square is formed by the intersection of Fifth Avenue and Broadway at 23rd Street in the New York City borough of Manhattan. The square was named for James Madison, fourth President of the United States and the principal author of the American Constitution. Jackson, Kenneth T. (ed.), The Encyclopedia of New York City (1995) ISBN 0-300-05536-6

The focus of the square is Madison Square Park, a 6.8 acre (2.75 hectare) public park, which is bounded on the east by Madison Avenue (which starts at the park's southeast corner at 23rd Street); on the south by 23rd Street; on the north by 26th Street; and on the west by Fifth Avenue and Broadway as they cross.

The park and the square are at the northern (uptown) end of the Flatiron District neighborhood of Manhattan. The use of "Madison Square" as a name for the neighborhood has fallen off, and it is rarely heard.

Madison Square is probably best known around the world for lending its name to Madison Square Garden, which was a sports arena located just northeast of the park until 1925. The current Madison Square Garden, the fourth such building, is not in the area. Notable buildings around Madison Square include the Flatiron Building, the Met Life Tower, and the New York Life Building. A new exclusive luxury high-rise condominium tower, "One Madison Park", will rival the Met Life Tower in height.

Madison Square can be reached using local service on the R, W, and N lines of the subway at the 23rd Street and 28th Street Stations. In addition, local stops on the 6 and F and V lines are one block away at Park Avenue and Sixth Avenue, respectively.