Wilmington Airport (IATA: ILG, ICAO: KILG, FAA LID: ILG) (formerly known as New Castle Airport, New Castle County Airport, sometimes referred to as Wilmington-New Castle Airport, or to a lesser extent Wilmington/Philadelphia Regional Airport and Greater Wilmington Airport) is an airport located in unincorporated New Castle County, Delaware, near Wilmington, Delaware. Owned by New Castle County and operated under a lease agreement with the Delaware River and Bay Authority, it is five miles (8 km) south of Wilmington and about 30 miles (50 km) from Philadelphia, Pennsylvania. It is included in the Federal Aviation Administration (FAA) National Plan of Integrated Airport Systems for 2017–2021, in which it is categorized as a non-hub primary commercial service facility.

Federal Aviation Administration records say the airport had 642 passenger boardings (enplanements) in calendar year 2011 and 1,064 passenger boardings in 2012. Thanks to the inauguration of service by Frontier Airlines, 2013 enplanements increased to 52,456, though Frontier ceased its Delaware service in 2015. Frontier resumed service to Wilmington in February 2021 but discontinued service again in June 2022. Avelo Airlines has since started service to Wilmington in February 2023.