According to the United States Census Bureau, the town has a total area of 18.9 square miles (49.0 km²), of which 18.7 square miles (48.4 km²) is land and 0.23 square miles (0.6 km²), 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 23 miles (37 km) south-southwest of Pittsfield, 50 miles (80 km) west of Springfield, 140 miles (230 km) west of Boston, and 48 miles (77 km) southeast of Albany, New York.

Egremont is situated in a valley east of the Taconic Range.
To the southwest, Mount Whitbeck divides the town from Mount Washington, and to the west, Mount Fray and several other mountains divide the town from New York proper.
Mount Fray is the site of the Catamount Ski Area, which extends into Hillsdale.
Mount Whitbeck and its neighbor, the Jug End, make up the Jug End State Reservation and Wildlife Management Area.
The Appalachian Trail extends through the reservation, before turning east at the Jug End towards Great Barrington.
The town lies along the Green River, a tributary of the Housatonic River.
Several brooks also flow through the town, with one being dammed to form the Mill Pond in South Egremont.

In South Egremont, Massachusetts Route 23 and Route 41 meet just northeast of the Mill Pond, traveling together into Great Barrington.
The western end of Route 23 is at the state border within town, where it becomes New York State Route 23.
Massachusetts Route 71, which carries part of the Knox Trail, also passes through the town, from Alford to the north to Great Barrington to the east.
The highway does not meet the other two, however, until well into Great Barrington.
The nearest interstate, Interstate 90 (the Massachusetts Turnpike), is located north of town, with the nearest exit, the "turn-around" Exit 1, being 12 miles (19 km) to the north in West Stockbridge.
There is no rail, bus or air service in town, with the nearest for all three being in Great Barrington.
The nearest national air service can be found at Albany International Airport in Albany, New York.
According to the United States Census Bureau, the town has a total area of 18.9 square miles (49.0 km²), of which 18.7 square miles (48.4 km²) is land and 0.23 square miles (0.6 km²), 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 23 miles (37 km) south-southwest of Pittsfield, 50 miles (80 km) west of Springfield, 140 miles (230 km) west of Boston, and 48 miles (77 km) southeast of Albany, New York.
Egremont is situated in a valley east of the Taconic Range. To the southwest, Mount Whitbeck divides the town from Mount Washington, and to the west, Mount Fray and several other mountains divide the town from New York proper. Mount Fray is the site of the Catamount Ski Area, which extends into Hillsdale. Mount Whitbeck and its neighbor, the Jug End, make up the Jug End State Reservation and Wildlife Management Area. The Appalachian Trail extends through the reservation, before turning east at the Jug End towards Great Barrington. The town lies along the Green River, a tributary of the Housatonic River. Several brooks also flow through the town, with one being dammed to form the Mill Pond in South Egremont.
In South Egremont, Massachusetts Route 23 and Route 41 meet just northeast of the Mill Pond, traveling together into Great Barrington. The western end of Route 23 is at the state border within town, where it becomes New York State Route 23. Massachusetts Route 71, which carries part of the Knox Trail, also passes through the town, from Alford to the north to Great Barrington to the east. The highway does not meet the other two, however, until well into Great Barrington. The nearest interstate, Interstate 90 (the Massachusetts Turnpike), is located north of town, with the nearest exit, the "turn-around" Exit 1, being 12 miles (19 km) to the north in West Stockbridge. There is no rail, bus or air service in town, with the nearest for all three being in Great Barrington. The nearest national air service can be found at Albany International Airport in Albany, New York.
Egremont, Massachusetts