How many counties are located on Long Island, N.Y. ?

There are 4 counties located on Long Island. The westernmost end of Long Island contains the New York City boroughs of Brooklyn (Kings County) and Queens (Queens County). The central and eastern portions contain the suburban Nassau and Suffolk counties. However, colloquial usage of the term "Long Island" usually refers only to Nassau and Suffolk counties. For example, the Federal Reserve Bank of New York has a district named "Long Island (Nassau-Suffolk Metro Division). At least as late as 1911, locations in Queens were still commonly referred to as being on Long Island. Some institutions in the New York City section of the island use the island's names, like Long Island University and Long Island Jewish Medical Center.