The Common is a park area with a playground, baseball field, and a number of monuments, several relating to the Revolutionary War.

Massachusetts Avenue enters from the southeast (a few miles after crossing the Charles River from Boston at MIT), and turns sharply to the north at the intersection, which is dominated by a large pedestrian space incorporating the current MBTA subway headhouse (entrance), an older subway headhouse building which formerly housed a newsstand, a visitor information kiosk, and a small open-air performance space ("The Pit").

The Harvard/MIT Cooperative Society main building forms the western streetwall at the intersection, along with a bank and some retail shops.

Until 1984, the Harvard Square stop was the northern terminus of the Red Line, and it still functions as a major transfer station between subway, bus, and trackless trolley.

A public motion art installation, Lumen Eclipse, shows monthly exhibitions of local, national, and international artists.

[7] This memorial, created by sculptor Konstantin Simun, pays tribute not only to the late puppeteer, but to all street performers that are an integral part of the square.

Although today a commercial center, the Square had famous residents in earlier periods, including the colonial poet Anne Bradstreet.

[1] In 1981 and 1987 the Harvard Square Theater was converted into a multiplex cinema; it later became part of the Loews Cineplex Entertainment chain and then closed on July 8, 2012.

[8] During the late 1990s, some locally run businesses with long-time shopfronts on the Square—including the unusual Tasty Diner, a tiny sandwich shop open long hours, and the Wursthaus, a German restaurant with an extensive beer menu—closed to make way for national chains.

Elsie's Lunch, a long-popular deli, has also closed; what remained of its small corner storefront space facing Lowell House on Mount Auburn Street is now occupied by an ATM.

Globe Corner Bookstore converted to an exclusively online business, serving its last walk-in customer on July 4, 2011.

The 1969 film Goodbye, Columbus takes place in Harvard Square near the film's conclusion, after the Richard Benjamin character learns that his girlfriend, Brenda Potimkin (played by Ali MacGraw), an undergraduate at Radcliffe College, had left her diaphragm in the top drawer of her bureau at home for her mother to discover.

[13] Ben Affleck shot portions of his film The Town (2010) in Grendel's Den on Winthrop Street, locally famous in the 1970s for its chocolate fondue.

[15] At the beginning of every episode, hosts Tom and Ray Magliozzi would state they were broadcasting from "Car Talk Plaza" in Harvard (though the show itself was recorded at the WBUR Studio in Boston).

[16][17] Local tourism and business leaders likewise refer to the area colloquially as "Car Talk Plaza".

[15] In 2019, a commemorative plaque for Tom Magliozzi - who died in 2014 - was installed outside the Abbott Building beside the Harvard Red Line terminal.