Chalgrove Airfield is a former Second World War airfield in Oxfordshire, England. The airfield is located approximately north-northeast of Benson; about north-northwest of London. Opened in 1943, it was used by both the Royal Air Force and United States Army Air Forces. During the war it was used primarily as a combat reconnaissance airfield. After the war it was closed in late 1946. Today, the airfield is primarily used by the Martin-Baker company for testing ejector seats.