Jefferson is a town in Lincoln County, Maine, United States. The population was 2,427 at the 2010 census. Damariscotta Lake State Park, a popular Mid Coast swimming, canoeing and picnic area, is located within the town limits.

Town of Jefferson was incorporated on February 24, 1807, when Thomas Jefferson was President, from Ballstown Plantation. During the 19th Century, it set off land to Alna and Newcastle, and annexed land from Patricktown, later incorporated as Somerville.

Abandoned granite quarries and clay banks where bricks were made suggest the early economic activities of the area.