Grundy Municipal Airport (ICAO: KGDY, FAA LID: GDY) was a public-use airport located three nautical miles (6 km) southwest of the central business district of Grundy, a town in Buchanan County, Virginia, United States. It was publicly owned by the Town of Grundy and was operated by the Grundy Municipal Airport Commission. Grundy Municipal was the only airport operating in Buchanan County. Small personal and charter planes used the facility. It was a 3 miles (5 km) drive from Grundy, the county seat of Buchanan County.

Although most U.S. airports use the same three-letter location identifier for the FAA and IATA, this airport was assigned GDY by the FAA but had no designation from the IATA.

Airport is now permanently closed as of October 31, 2019.