Searsport was settled in the 1670s, and incorporated from portions of Prospect and Belfast on February 13, 1845. It was named after David Sears of Boston, who was one of the ten who bought land in the area which had been held by the heirs of General Samuel Waldo, as he granted a large sum towards the town's founding. In 1747, after a fire destroyed the Province House in Boston, General Waldo advocated, unsuccessfully, to move the capital of Massachusetts to Searsport, which was part of the Waldo Patent he purchased in 1720.
The town is known for its maritime history. During the 19th century, Searsport had seventeen shipyards which built two hundred ships, and one tenth of the nation's Merchant Marine deep water captains came from Searsport.