According to the United States Census Bureau, the town has a total area of 13.2 square miles (34.1 km2), of which 12.9 square miles (33.3 km2) is land and 0.31 square miles (0.8 km2), or 2.20%, is water. Georgetown is located on the edge of the hills and coastal plain of northeastern Massachusetts. It has many streams and brooks, as well as two major ponds, Rock Pond and Pentucket Pond. The town has several areas of protected land, including the Georgetown-Rowley State Forest to the south, the Crane Pond Wildlife Management Area to the north, the Lufkins Brook Area to the west, and a small portion of the Boxford State Forest in the southwest.
Georgetown is located approximately 10 miles (16 km) east of Lawrence and 28 miles (45 km) north of Boston, north of the center of Essex County. It is bordered by Groveland to the northwest, Newbury to the northeast, Rowley to the southeast, and Boxford to the southwest. Interstate 95 crosses through the eastern half of town, with one exit within the town, at Route 133. Route 133 crosses from east to west through town, with Route 97 crossing from northwest to south. Both state routes share a short stretch of road near the town center. The town has no mass transit; the nearest rail service can be found along the Newburyport/Rockport Line of the MBTA Commuter Rail in Rowley. The nearest air service is at Logan International Airport.