Falmouth lies on the southwestern tip of Cape Cod. It is bordered by Bourne and Sandwich to the north, Mashpee to the east, Vineyard Sound to the south, and Buzzards Bay to the west. At its closest point, Falmouth is approximately from Nonamesset Island, the easternmost island of the town of Gosnold and the Elizabeth Islands. It is approximately north-northwest of Martha's Vineyard, the closest land to the island. Falmouth is approximately south of the Bourne Bridge, west of Barnstable, and south-southeast of Boston.