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 streets above Pennsylvania Station. It is the fourth venue to bear the name "Madison Square Garden"; the first two, opened in 1879 and 1890 respectively, 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.

The Garden hosts professional ice hockey, professional basketball, boxing, mixed martial arts, concerts, ice shows, circuses, professional wrestling, and other forms of sports and entertainment. It is close to other midtown Manhattan landmarks, including the Empire State Building, Koreatown, and Macy's at Herald Square. It is home to the New York Rangers of the National Hockey League (NHL), the New York Knicks of the National Basketball Association (NBA), and was home to the New York Liberty of the Women's National Basketball Association (WNBA) from 1997 to 2017.

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 in the NHL, after Seattle's Climate Pledge Arena. As of 2016, MSG is also the second-busiest music arena in the world in terms of ticket sales. Including its two major renovations in 1991 and 2013, the Garden's total construction cost was approximately $1.1 billion, and it has been ranked as one of the 10 most expensive arena 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.