Mastic Beach is a village in the southeast part of the town of Brookhaven in Suffolk County, New York, United States. The population was 12,930 at the 2010 census, at which time it was an unincorporated census-designated place. The village is located in the general vicinity of the hamlet of Mastic Beach.
Mastic Beach is on a peninsula extending into Moriches Bay. Created in 1928, there are marinas, private docks, and several historic sites. There is sailing, swimming, fishing, birding, hiking, camping and shopping.
Mastic Beach is served by the William Floyd School District.