Hōryū-ji (法隆寺^?, lit. Temple of the Flourishing Law) is a Buddhist temple in Ikaruga, Nara Prefecture, Japan. Its full name is Hōryū Gakumonji (法隆学問寺), or Learning Temple of the Flourishing Law, the complex serving as seminary and monastery both.

The temple's pagoda is widely acknowledged to be one of the oldest wooden buildings existing in the world, underscoring Hōryū-ji's place as one of the most celebrated temples in Japan. In 1993, Hōryū-ji was inscribed together with Hokki-ji as a UNESCO World Heritage Site under the name Buddhist Monuments in the Hōryū-ji Area. The Japanese government lists several of its structures, sculptures and artifacts as National Treasures.

The temple was originally commissioned by Prince Shōtoku; at the time it was called Ikaruga-dera (斑鳩寺), a name that is still sometimes used. This first temple is believed to have been completed by 607. Hōryū-ji was dedicated to Yakushi Nyorai, the Buddha of healing and in honor of the prince's father. Excavations done in 1939 confirmed that Prince Shotoku's palace, the Ikaruga-no-miya (斑鳩宮), occupied the eastern part of the current temple complex, where the Tō-in (東院) sits today. Also discovered were the ruins of a temple complex which was southwest of the prince's palace and not completely within the present temple complex. The original temple, named by modern historians and archaeologists Wakakusa-garan (若草伽藍), was lost, probably burned to the ground after being hit by lightning in 670. The temple was reconstructed but slightly reoriented in a northwest position, which is believed to have been completed by around 711. The temple was repaired and reassembled in the early twelfth century, in 1374, and 1603.