is a census-designated place (CDP) in Suffolk County, New York, United States. The population was 11,131 at the 2000 census.
According to the United States Census Bureau, the CDP has a total area of 25.4 square miles (65.8 km²), of which, 25.4 square miles (65.7 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.16%) is water.
The town is characterized by its location at the western edge of, and partially within, the Long Island Central Pine Barrens. As such, the land is heavily wooded, and features some wetlands, particularly in the northern section near the Peconic River. Much of the northeastern portion of the town is in the Pine Barrens' "Core Preservation Area", where no further development is allowed. This area also serves as a primary source for Long Island's groundwater preserve.
Manorville lies at the center of Long Island, and as such, has no access to the water. It also lies partially on the Ronkonkoma terminal moraine, which creates some slightly rolling topography, especially in the central portion of the town. The glacial topography of the area features several kettle hole ponds, the most well-known of which is known as Punk's Hole, where a Revolutionary War captain was rumored to have hid from the British.