The Thirteen Buddhas is a Japanese grouping of Buddhist deities, particularly in the Shingon sect of Buddhism. The deities are, in fact, not only Buddhas, but include bodhisattvas and Wisdom Kings. In Shingon services, lay followers recite a devotional mantra to each figure, though in Shingon practice, disciples will typically devote themselves to only one, depending on what the teacher assigns. Thus the chanting of the mantras of the Thirteen Buddhas are merely the basic practice of laypeople.

Shingon is one of the major schools of Buddhism in Japan and one of the few surviving Vajrayana lineages in East Asian Buddhism. It is sometimes also called Japanese Esoteric Buddhism, or Eastern Esotericism. The word shingon is the Japanese reading of the Chinese word 真言, which is the translation of the Sanskrit word mantra.