It is located in the region of the island usually referred to as Mid-Island, immediately to the south of Port Richmond, to the west of Meiers Corners and Westerleigh, to the north of New Springville, and to the east of Bulls Head.
Named for a brook that flowed through the area's farmland, Willowbrook once lay at the heart of the island's agricultural zone, and first saw other significant development when a military hospital opened there during World War II.
The facility was forced to close by 1987, and six years later a campus of the College of Staten Island opened at the site.
It was also home to the Seaview Hospital tuberculosis sanatorium, added to the National Register of Historic Places in 2005.
The New York Public Library (NYPL)'s Todt Hill-Westerleigh branch is located at 2550 Victory Boulevard on the border between Willowbrook and Westerleigh.