Massapequa is a hamlet (and a census-designated place) in the southern part of the Town of Oyster Bay in southeastern Nassau County, New York. As of the 2010 census, the CDP had a total population of 21,685.

For many years it was reported that Massapequa was one of the 13 tribes of Long Island. Later research says that it was the Native American name for the location.

Massapequa, on the South Shore of Long Island, is located at 40°40'13" North, 73°28'16" West (40.670403, -73.471150).

According to the United States Census Bureau, the CDP has a total area of 4.0 square miles (10 km²), of which, 3.7 square miles (9.6 km²) of it is land and 0.4 square miles (1.0 km²) of it is water. The total area is 9.20% water.

Massapequa and nearby places with "Massapequa" in their names are sometimes collectively called "the Massapequas".

As of the census of 2000, there were 22,652 people, 7,417 households, and 6,297 families residing in the CDP. The population density was 6,207.5 per square mile (2,396.2/km²). There were 7,514 housing units at an average density of 2,059.1/sq mi (794.8/km²). The racial makeup of the CDP was 97.42% White, 0.17% African American, 0.02% Native American, 1.27% Asian, 0.03% Pacific Islander, 0.37% from other races, and 0.73% from two or more races. 2.59% of the population were Hispanic or Latino of any race.

John Ward Melville (January 5, 1887 - June 5, 1977) was an American philanthropist and businessman active in the "Three Villages" in western Suffolk County, Long Island, New York. He donated 400 acres of land and money to establish the State University of New York at Stony Brook in 1957, which has developed as a major public research institution.

He was born to Frank Melville, Jr. and his wife. Ward Melville attended college at Columbia University, where he was active in the Columbia Daily Spectator and the Philolexian Society.

After joining his father in his company, in 1909 Melville married Dorothy Bigelow.

Following graduation in 1909, Melville joined his father's shoe company, Melville Corporation. Upon the United States' entrance in World War I, Melville became a soldier of the US Army.

After the war, Melville continued to work in his father's company, eventually taking control of it in 1922. At the time, he created the Thom McAn shoe line, which became popular. He was CEO of the corporation.