is a seventh-century Buddhist temple in Dazaifu, Fukuoka, Fukuoka Prefecture, Japan. It was once the most important temple in Kyushu. Its bell, one of the oldest in the country, has been designated a National Treasure, and in 1996 the Ministry of the Environment designated its sound as one of the 100 Soundscapes of Japan. Many of its statues from the Heian period are Important Cultural Properties.
The origins of Kanzeon-ji are uncertain, and its oldest known appearance in historical documentation is in the Kanzeon-ji Zaizaicho (National Treasure, owned by Tokyo University of the Arts), compiled in 905. According to the Shoku Nihongi, Kanzeon-ji was founded by Emperor Tenji in honour of his mother Empress Saimei. As she died in 661, it is assumed that construction began shortly thereafter; however, it was still incomplete fifty years later when additional workers were assigned in 709. A further entry in the Shoku Nihongi indicates that it was completed in 746. The oldest roof tiles excavated from the temple grounds date to the 7th century and have patterns of double-valved, eight-petaled lotus-shaped eaves and eccentric arabesque patterns also found in Fujiwara-kyà  and Kawara-dera in Asuka, Nara. The bonshà  bell at Kanzeon-ji was cast using the same wooden mold as the bell at Myà Âshin-ji in Kyoto, which has the date inscription of 698.
All of the original structures of Kanzeon-ji have been lost and rebuilt repeatedly due to fires and other disasters. Excavation has revealed that the original layout of the temple was patterned after Kawara-dera, with a south gate, middle gate, Kondà  (Main Hall) to the west, pagoda to the east, and a lecture hall in the centre, with a cloister. In 761, the monk Ganjin constructed a Kaidan-in, which permitted monks trained at this temple to be fully ordained without having to travel all the way to the capital. In 1064, a fire destroyed the lecture hall and pagoda. In 1102, the Kondà Â, South Gate, and other buildings collapsed due to a strong wind. The Kondà  was later restored, but it was destroyed again in a fire in 1143. The temple went into decline in the Muromachi and Sengoku periods, and by 1630, its only remaining main hall collapsed during a rainstorm, and Kanzeon-ji was reduced to an abandoned temple.
In 1631, a new Kondà  was built under the sponsorship of the Kuroda clan of Fukuoka Domain. The Kondà  and lecture hall were rebuilt in the Genroku era (1688-1703). These structures are now designated Fukuoka Prefectural Tangible Cultural Properties. From 1913 to 1914, repairs were made to the badly damaged Buddha statues. In 1959, the reinforced concrete treasure house was completed. This was one of the earliest temple cultural property repositories built.
The were declared a National Historic Site in 1970.
A Heian period dating to 905 and now in Tokyo has been designated a National Treasure.