Harvard Square is a triangular plaza at the intersection of Massachusetts Avenue, Brattle Street and John F. Kennedy Street near the center of Cambridge, Massachusetts, United States. The term "Harvard Square" is also used to delineate the business district and Harvard University surrounding that intersection, which is the historic center of Cambridge. Adjacent to Harvard Yard, the historic heart of Harvard University, the Square functions as a commercial center for Harvard students, as well as residents of western Cambridge, the western and northern neighborhoods and the inner suburbs of Boston. The Square is served by Harvard station, a major MBTA Red Line subway and a bus transportation hub.

Brattle Street in Cambridge, Massachusetts, called the "King's Highway" or "Tory Row" before the American Revolutionary War, is the site of many buildings of historical interest, including the modernist glass-and-concrete building that housed the Design Research store, and a Georgian mansion where George Washington and Henry Wadsworth Longfellow both lived, as well as John Vassall and his seven slaves including Darby Vassall. Samuel Atkins Eliot, writing in 1913 about the seven Colonial mansions of Brattle Street's "Tory Row," called the area "not only one of the most beautiful but also one of the most historic streets in America." "As a fashionable address it is doubtful if any other residential street in this country has enjoyed such long and uninterrupted prestige."