Tianxi Zai (天息灾), active during the Northern Song Dynasty, was a prolific translator of Buddhist scriptures from Sanskrit into Chinese. He is particularly known for his translation of the *Mahāprajñāpāramitā-hr̥daya Sūtra* (Heart Sutra) and the *Uṣṇīṣa-vijaya Dhāraṇī Sūtra*.