Market Square (San Francisco)

Market Square
The building in May 2023
Former names	Western Furniture Exchange and Merchandise Mart San Francisco Mart
Alternative names	Twitter Building
General information
Architectural style	Art Deco (Additional elements of Mayan Revival and International Style)
Address	1355 Market Street
Town or city	San Francisco, California
Country	United States
Coordinates	37°46′35″N 122°25′01″W / 37.77639°N 122.41694°W / 37.77639; -122.41694
Year(s) built	1936–1937
Opened	July 31, 1937 (Dedication ceremony) August 3, 1937 (Official opening)
Owner	JPMorgan Chase Shorenstein Properties
Landlord	Shorenstein Properties
Technical details
Floor count	11
Floor area	1,000,000 square feet (93,000 m2)
Design and construction
Architecture firm	Capital Co. Architects

Market Square (formerly the Western Furniture Exchange and Merchandise Mart, the San Francisco Mart, and, colloquially, the Twitter Building) is an Art Deco building in the Mid-Market neighborhood of San Francisco, California, United States. Located at 1355 Market Street, it was constructed in 1937 and originally served as a showroom for retailers and wholesalers in the furniture industry. In the early 21st century, the building underwent an extensive conversion into office and retail space, and today is most well known as the headquarters for X Corp., the owner of the social networking service X (formerly Twitter).