Anasuya (Sanskrit: अनसूया, romanized: Anasūyā, lit. 'free from envy and malice') is an ascetic, and the wife of Sage Atri in Hinduism. She is the daughter of Devahuti and the Prajapati Kardama in Hindu texts. In the Ramayana, she lives with her husband in a small hermitage on the southern border of the Chitrakuta forest. A pious woman who leads an austere life, she is described as having miraculous powers.

Anasuya is the sister of the sage Kapila, who also served as her teacher. She is extolled as Sati Anasuya (Ascetic Anasuya) and Mata Anasuya (Mother Anasuya), the chaste wife of Sage Atri. She becomes the mother of Dattatreya, the sage-avatar of Vishnu, Chandra, a form of Brahma, and Durvasa, the irascible sage avatar of Shiva. When Sita and Rama visit her during their exile, Anasuya is very attentive to them, giving the former an unguent that would maintain her beauty forever.

Anasuya is composed of two Sanskrit words: ana and asūya, translating to the 'one who is free from jealousy or envy'.

The genealogy of Anasuya and her family is mentioned in the third book of the Bhagavata Purana. The Prajapati Kardama marries Devahuti, the daughter of the Svayambhu Manu. They are described to have ten children, a son named Kapila, and nine daughters, including Anasuya. Each daughter is married to a rishi; Anasuya is married to Atri.

According to a legend from the Markandeya Purana, a Brahmin named Kaushika from Pratishthana used to visit a prostitute, despite having a devoted wife, named Shandili, or Shilavati, or Sumati in some versions. When he is unable to pay her for her services, the prostitute stops seeing him, forcing him to return to his wife, who still cares for him. As he still longs for the affection of the prostitute, he asks his wife to take him to her.

The sage Mandavya had been impaled in lieu of a crime and was lying on a spike in the forest, still alive due to his yogic powers. While being led by his wife through the deep forest at night, Kaushika, mistaking the sage for a thief, pushes him. Furious, Mandavya curses him to die before the next sunrise. To stop this curse from fruition, Shandili appeals to the solar deity, Surya, to not rise the next dawn. Surya acquiesces to the appeal of Shandili, as she is an extremely chaste and devoted woman. This leads to chaos in the universe, the deities not receiving their oblations, rainfall not occurring, grain not being cultivated, and people not performing their customary Vedic rituals. The deities go to Brahma, who suggests that they propitiate Anasuya, who was in the process of performing a great tapas with her husband.

Accordingly, the divinities go to Anasuya, and the kind-hearted woman agrees to help them. Anasuya meets Shandili, and the two women engage in a conversation. Anasuya explains to Shandili that the entire universe is in peril because of her appeal to Surya, and discusses the necessity of a woman's devotion to her husband. Anasuya promises the woman that Kaushika would be free of his curse, as well as the leprosy he had contracted. Shandili directs the sun to rise again, and thus, Anasuya helps in the restoration of the sunrise. The deities, pleased by her actions, offer her a boon. Anasuya desires that the Trimurti (The supreme trinity of Brahma, Vishnu, and Shiva) be born to her, and that her husband and she be freed of the cycle of samsara. This boon is granted when Anasuya is mentally impregnated by Atri, and Chandra (Brahma), Dattatreya (Vishnu), and Durvasa (Shiva) are born to her as her sons.

Some legends state that later, when Rahu swallowed the sun, the whole world was cloaked in darkness. With powers granted by many years of austerity, Atri wrested the sun out of Rahu's hands, restoring light to the world, and pleasing the deities.