Sannyasa (Devanagari: संन्यास, saṁnyāsa) is the life stage of the renouncer within the Hindu scheme of āśramas. It is considered the topmost and final stage of the ashram systems and is traditionally taken by men or women over fifty or by young monks who wish to renounce worldly and materialistic pursuits and dedicate their lives to spiritual pursuits. People in this stage of life develop vairāgya, or a state of dispassion and detachment from material life, renouncing worldly thoughts and desires in order to spend the remainder of their lives in spiritual contemplation. A member of the sannyasa order is known as a sannyasin (male) or sannyasini (female).

During the sannyasa phase of life, a person abandons fire, or Agnihotra, allowed to the Grihastha ashram or householder phase of life. People who have entered the sannyasa ashram may choose not to cook, perform fire rituals or take heat from fire. In practice, however, Sannyasis do various services and partake in sacred rituals to set an example for others. Sannyasa focuses only on the self and spirituality and not even the gods (as abandoning fire suggests). Symbolically, a sannyasi casts his physical body into fire by wearing saffron robes when entering this phase, thus freeing the soul while the body is still alive. Hence, sannyasis are not cremated after death as most Hindus are, but may instead be buried.