Halesite is a hamlet and census-designated place (CDP) in the Town of Huntington on the North Shore of Long Island in Suffolk County, New York, United States. The population was 2,498 at the 2010 census.
Halesite is named after Nathan Hale, a captain and spy in the Continental Army during the American Revolutionary War who arrived on Long Island at Huntington Harbor (at the site now named Halesite) just prior to his capture and execution. There is a rock with a tribute to him off of the traffic circle at Mill Dam Road and New York Avenue.
From the mid-19th century until about the time of World War I, Halesite was served by a trolley line which brought passengers from Amityville through Downtown Huntington to the end of New York Avenue, at the northwest end of Halesite. Tourists were able to enjoy Halesite Park, which commands a view of Huntington Harbor.
Well-known persons who spent time or lived in Halesite include comedian/singer Fanny Brice and scientist Albert Einstein.
The area has been protected by the Halesite Fire Department since 1901. The Halesite Fire Department also protects the incorporated village of Huntington Bay. Halesite is also served by a United States Post Office branch, although its zip code is the same as that of the hamlet of Huntington (11743). Huntington Hospital sits along the southern boundary of Halesite.