The 16th Suffolk County Legislative District (L.D.) includes Commack, Dix Hills, East Northport, Elwood, Melville and South Huntington in the Town of Huntington, Deer Park in the Town of Babylon and Brentwood and North Bay Shore in the Town of Islip. The district is bounded roughly by Clay Pitts Road to the North, Sunrise Highway to the South, New York Avenue to the West and Washington Avenue and Awixa Creek to the East.
It consists of (62) election districts (ED.s) with 49,307 registered voters. The 16th L.D. has 6 ED.s in the Town of Babylon, 39 ED.s in the Town of Huntington and 17 ED.s in the Town of Islip.