Henry C. Mustin Naval Air Facility, also known as NAF Mustin Field, is a former military airfield located at the United States Navy Naval Aircraft Factory on board the Philadelphia Naval Shipyard, Philadelphia, Pennsylvania. It was in service from 1926 to 1963.

The Naval Aircraft Factory (NAF) was established by the United States Navy in 1918 in Philadelphia, Pennsylvania. It was created to help solve aircraft supply issues which the Navy Department faced upon the entry of the U.S. into World War I. The United States Army’s requirements for an enormous quantity of airplanes created a decided lack of interest among aircraft manufacturers in the Navy's requirements for a comparatively small quantity of aircraft. The Navy Department concluded that it was necessary to build a Navy-owned aircraft factory in order to assure a part of its aircraft supply; to obtain cost data for the department’s guidance in its dealings with private manufacturers; and to have under its own control a factory capable of producing experimental designs.