Aquinnah is a town located on the western end of Martha's Vineyard island, Massachusetts, United States. From 1870 to 1997, the town was incorporated as Gay Head. At the 2020 U.S. census, the population was 439. Aquinnah is known for its beautiful clay cliffs and natural serenity, as well as its historical importance to the native Wampanoag people. In 1965, Gay Head Cliffs were designated as a National Natural Landmark by the National Park Service.