Melville is a hamlet and census-designated place in the Town of Huntington in Suffolk County, on Long Island, in New York, United States. The population was 19,284 at the time of the 2020 census. The area was known to the Native Americans as Sunsquams. In the 17th century, it was named Samuel Ketcham's Valley, and it was later known as Sweet H…Melville is a hamlet and census-designated place in the Town of Huntington in Suffolk County, on Long Island, in New York, United States. The population was 19,284 at the time of the 2020 census. The area was known to the Native Americans as Sunsquams. In the 17th century, it was named Samuel Ketcham's Valley, and it was later known as Sweet Hollow.