Mattituck is believed to have derived its name from the Native American name for "Great Creek". Mattituck Creek has been dredged and is used extensively by pleasure craft on Long Island Sound (the Mattituck Inlet is the entrance into Mattituck Creek, and the whole waterway is now popularly referred to as Mattituck Inlet).
It is only one of two harbors (the other being Mt. Sinai harbor) on the north side of Long Island on the Sound east of Port Jefferson.
The Mattituck Inlet and James Creek (which has also been dredged for boats) on the Peconic Bay come within of each other and would provide a shortcut between the Peconic and Sound through the North Fork if connected via a canal. However, authorities have resisted the connection, fearing an ecological disaster. Still, the inlet is blamed for coastal erosion because it interrupts the longshore drift on the sound.
Corchaug Indians, who were the first residents of the area, sold land to Theophilus Eaton, governor of New Haven, Connecticut. The area was eventually settled by English colonists. The meadowlands were held in common by the residents of Southold from its founding in 1640. The town of Southold was established by Charter to the New Haven Colony of Connecticut in 1658. The woodlands were also held in common until 1661, when that land was divided among individual proprietors.
Mattituck hosts an annual Strawberry Festival and is located in the heart of over 30 vineyards in the Long Island Wine Region.