Madison Square Garden, colloquially known as the Garden or by its initials MSG, is a multi-purpose indoor arena in New York City. It is located in Midtown Manhattan between Seventh and Eighth Avenues from 31st to 33rd Street above Pennsylvania Station. It is the fourth venue to bear the name "Madison Square Garden"; the first two, 1879 and 1890, were located on Madison Square, on East 26th Street and Madison Avenue, with the third Madison Square Garden (1925) farther uptown at Eighth Avenue and 50th Street.

Originally called Madison Square Garden Center, the Garden opened on February 11, 1968, and is the oldest major sporting facility in the New York metropolitan area. It is the oldest arena in the NBA and the second oldest arena in the NHL. As of 2016, MSG is also the second-busiest music arena in the world in terms of ticket sales. Including two major renovations, its total construction cost was approximately $1.1 billion, and it has been ranked as one of the 10 most expensive stadium venues ever built. It is part of the Pennsylvania Plaza office and retail complex, named for the railway station. Several other operating entities related to the Garden share its name.