Cos Cob is located in Fairfield County just west of Stamford between Darien and Port Chester along Highway 1 near Putnam Lake. Located in the southwestern most corner of Connecticut, Cos Cob sits on the coastline of the Long Island Sound.

Community derives from the Algonquian language which means "high rock." The town Cos Cob was incorporated not much after Greenwich.

It had an artist colony, known as the Cos Cob School, in the late 1800s and early 1900s and a new one growing now. Situated on Cos Cob Harbor on Long Island Sound, the community's role as a commercial shipping port disappeared with the damming of the Mianus River.

Local attractions include: Cos Cob Harbor, Greenwich Creek, Mianus River, Fyre Lake, Putnam Lake, and Bruce Museum. There is nearby shopping in Stamford.

Bush-Holley Historic Site in Cos Cob is the home of Connecticut's first art colony, the 1730's House neighborhood inspired over 200 artists between 1890 and 1920, including American Impressionists Twachtman, Hassam, Lawson, and MacRae whose works and the site's history are presented through tours, including the 19th-century Cos Cob Post Office - now a visitor center with changing exhibitions. Film and archive documents the colony's origins.

The Bush-Holley House is a National Historic Landmark in Greenwich, Connecticut. It was constructed circa 1730 and in the late nineteenth century was a boarding house and the center of the Cos Cob art colony.