For the airport near Cave Junction, Oregon, see Illinois Valley Airport

Illinois Valley Regional Airport (IATA: VYS, ICAO: KVYS, FAA LID: VYS), also known as Walter A. Duncan Field, is a city-owned, public-use airport located 1 nautical mile (1.9 km; 1.2 mi) northwest of the central business district of Peru, a city in LaSalle County, Illinois, United States. The airport was opened in November 1985. The airport hosts the TBM Avenger Reunion every year in May.

The airport also has a flying club that offers aircraft rental, flight training, and events such as fly-in breakfasts.