During the reign of the Mauryan Emperor Ashoka (273–232 BCE), Buddhism gained royal support and began to spread more widely, reaching most of the Indian subcontinent. After his invasion of Kalinga, Ashoka seems to have experienced remorse and began working to improve the lives of his subjects. Ashoka also built wells, rest-houses and hospitals for humans and animals. He also abolished torture, royal hunting trips and perhaps even the death penalty. Ashoka also supported non-Buddhist faiths like Jainism and Brahmanism. Ashoka propagated religion by building stupas and pillars urging, among other things, respect of all animal life and enjoining people to follow the Dharma. He has been hailed by Buddhist sources as the model for the compassionate chakravartin (wheel turning monarch). King Ashoka sends first Buddhists to Sri Lanka in the third century.

Another feature of Mauryan Buddhism was the worship and veneration of stupas, large mounds which contained relics (Pali: sarīra) of the Buddha or other saints within. It was believed that the practice of devotion to these relics and stupas could bring blessings. Perhaps the best-preserved example of a Mauryan Buddhist site is the Great Stupa of Sanchi (dating from the 3rd century BCE).