In Hinduism, sādhu (skt साधु sādhu, "good; good man, holy man") denotes an ascetic, wandering monk. Although the vast majority of sādhus are yogīs, not all yogīs are sādhus. The sādhu is solely dedicated to achieving mokṣa (liberation), the fourth and final aśrama (stage of life), through meditation and contemplation of brahman. Sādhus often wear saffron-colored clothing, symbolizing their sanyāsa (renunciation).

This way of life is open to women; the female form of the word is sādhvī साध्वी.