Herlong Recreational Airport (ICAO: KHEG, FAA LID: HEG), also known as Herlong Field, then Herlong Airport, is a public airport located eight nautical miles (13 km) southwest of the central business district of Jacksonville, a city in Duval County, Florida, United States.

[1][2] This airport is assigned a three-letter location identifier of HEG by the Federal Aviation Administration, but it does not have an International Air Transport Association (IATA) airport code.

The airport was originally built during World War II to facilitate pilot training for the Navy and Air Force.

[1] For the 12-month period ending October 20, 1999, the airport had 80,700 aircraft operations, an average of 221 per day: 97% general aviation and 3% military.

There are 162 aircraft based at this airport: 70% single-engine, 9% multi-engine, 10% ultralight, 8% glider and 2% helicopter.