Buddhist monastic order, traditionally composed of four groups: monks, nuns, laymen, and laywomen. The sangha is a part—together with the Buddha and the dharma (teaching)—of the Threefold Refuge, a basic creed of Buddhism.

The sangha originated in the group of disciples who renounced the worldly life to wander with the Buddha and listen to his teachings. After the Buddha's death his disciples continued to live together as a community, wandering from place to place, living off the receipt of alms. Fortnightly, at the time of the full and new moon (the uposatha days), followers of the Buddha would gather to reaffirm their sense of community and purpose by reciting their basic beliefs, such as the Threefold Refuge and the codes of conduct. The custom of spending the rainy season in one place in a study retreat (see vassa) led gradually to the settling of the community.

The modern sangha is governed by disciplinary rules (vinaya) that form part of the sacred canon. Generally, the monastic order is dependent on the lay community for economic support in the form of alms or large gifts of money and property, since Buddhist monks—notably those of the Theravāda tradition in Southeast Asia—do not engage in commerce or agriculture.