John W. McCormack Post Office and Courthouse

	United States Post Office, Courthouse, and Federal Building
	U.S. National Register of Historic Places
Location	5 Post Office Square; Boston, Massachusetts
Coordinates	42°21′26″N 71°3′25″W / 42.35722°N 71.05694°W
Area	2.2 acres (0.89 ha)
Built	1931–1933
Architectural style	Art Deco
NRHP reference No.	11000160
Added to NRHP	April 8, 2011

The John W. McCormack Post Office and Courthouse, formerly the United States Post Office, Courthouse, and Federal Building is a historic building at 5 Post Office Square in Boston, Massachusetts. The twenty-two story, 331-foot (101 m) skyscraper was built between 1931 and 1933 to house federal courts, offices, and post office facilities. The Art Deco and Moderne structure was designed in a collaboration between the Supervising Architect of the United States Treasury Department and the Boston architectural firm of Cram and Ferguson. It occupies a city block bounded by Congress, Devonshire, Water, and Milk Streets, and has over 600,000 square feet (56,000 m²) of floor space. The exterior of the building is faced in granite from a variety of New England sources, as well as Indiana limestone.^[2]

The building is named for John W. McCormack, a long-serving Boston Congressman who was Speaker of the House from 1962 to 1971.

The building was designated a Boston Landmark by the Boston Landmarks Commission in 1998 and listed on the National Register of Historic Places in 2011.^[1]