According to the United States Census Bureau, the town has a total area of , of which is land and , or 1.26%, is water. Egremont lies along the western border of Berkshire County and Massachusetts, with Columbia County, New York, to the west. The town is bordered by Alford to the north, Great Barrington to the east, Sheffield to the southeast, Mount Washington to the southwest, and Copake and Hillsdale, New York, to the west. Egremont is south-southwest of Pittsfield, west of Springfield, west of Boston, and southeast of Albany, New York.