The New York Harbor Storm-Surge Barrier is a proposed flood barrier system to protect the New York-New Jersey Harbor Estuary from storm surges. The proposed system would consist of one barrier located across the mouth of Lower New York Bay, possibly between Sandy Hook (N.J.) and Rockaway (N.Y.), and a second on the upper East River to provide a ring of protection to most of the bi-state region. Through extensive use of floodgates, both barriers would have largely open cross-sections during normal conditions to minimize environmental impacts on the estuary and port operations.

A flood barrier, surge barrier or storm surge barrier is a specific type of floodgate, designed to prevent a storm surge or spring tide from flooding the protected area behind the barrier. A surge barrier is almost always part of a larger flood protection system consisting of floodwalls, levees, and other constructions and natural geographical features.