Machiasport is a town in Washington County, Maine, United States.

In 1633, the Plymouth Company established a trading post here to conduct business with the Native Americans.

[3] In 1770, the area was granted by the Massachusetts General Court to 80 petitioners, 54 from Scarborough.

[4] In 1775, following the capture of the British ship HMS Margaretta by locals under leadership of Jeremiah O'Brien, the residents built a small breastworks here to guard the mouth of the Machias River and the area settlements.

Later that year, the British sent four ships under the command of Sir George Collier that defeated the local militia, destroyed the breastworks, and burned several buildings.

In 1781 it was made part of the national defense and named Fort O'Brien.

In 1808–1809, Lemuel Trescott of Eastport oversaw the construction of a blockhouse, barracks and battery.

During the War of 1812, in September 1814 the British captured the fort and burnt the barracks.

As of 2006, they are managed as a historic site by the Maine Bureau of Parks and Lands.

[7] Machiasport has been the setting of several ethnographic documentary films about its inhabitants by the anthropologist and filmmaker Anna Grimshaw.