The Mather House Museum in Port Jefferson, New York is local history museum complex that includes:
* the mid 19th century period Mather House house with furnished rooms, and local history and decorative art exhibits
* a craft house with a display of toys, spinning wheels and quilts
* a country store with items from a historic barber shop, general store and butcher shop
* a barn with shipbuilding and sailmaking artifacts
* a tool shed with shipbuilding and carpentry tools
* and a museum with antique clocks.
The house is the headquarters location for The Historical Society of Greater Port Jefferson. The house is located at 115 Prospect Street in Port Jefferson.