(Sanskrit: “Great Story”), important legendary life of the Buddha, produced as a late canonical work by the Mahāsaṅghika school of early Buddhism and presented as a historical introduction to the vinaya, the section of the canon dealing with monastic discipline. Its three sections treat the Buddha's former lives, the events from his entering the womb of Queen Mahā Māyā to his enlightenment, and his first conversions and the rise of the monastic community.

The text is exuberant in style, and in form, a labyrinth; its central narrative is frequently interrupted by Jātakas (explanations of present events by incidents in the Buddha's previous lives), Avadānas (similar tales from the previous lives of others), and doctrinal discourses. The life of the Buddha itself is presented as a profusion of miracles and wondrous events. The Mahāvastu reflects a growth of ideas about bodhisattvas (“buddhas-to-be”) that was to continue in Mahāyāna circles, but at the same time, it preserves many ancient stories, traditions, and textual passages. The core of the work may go back to the 2nd century BC, but much material was added about the 4th century AD. See also Lalitavistara.