Kongōbu-ji (金剛峯寺^?) is the ecclesiastic head temple of Koyasan Shingon Buddhism, located on Mount Kōya (高野山, Kōya-san^?), Wakayama prefecture, Japan. Its name means Temple of the Diamond Mountain. It is part of the "Sacred Sites and Pilgrimage Routes in the Kii Mountain Range" UNESCO World Heritage Site.

The temple was first constructed as Seigan-ji Temple in 1593 by Toyotomi Hideyoshi on the death of his mother, rebuilt in 1861, and given its present name in 1869. It contains many sliding screen doors painted by Kanō Tanyū (1602-1674) and members of Kyoto's Kanō school.