Aichi-Kōgen Quasi-National Park is a 21,705-hectare (53,630-acre) quasi-national park in the Tōkai region of Honshū in Japan. It is rated a protected landscape (category III) according to the IUCN. As with neighboring Hida-Kisogawa Quasi-National Park and Tenryū-Okumikawa Quasi-National Park the park includes mountainous landscapes with gorges and dense forests. The part is on the border between Shizuoka and Aichi Prefecture, but is entirely within Aichi. It also includes a portion of the Tōkai Nature Trail. It encompasses the area around Yahagi Dam and the Kourankei scenic areas. The area was designated a quasi-national park on December 28, 1970.