Satyanatha Tirtha (also known as Satyanatha Yati) (Sanskrit:सत्यनाथा तीर्थ); IAST:Śrī Satyanātha Tīrtha) (c.1648 – c.1674), also called Abhinava Vyasaraja, was a Hindu philosopher, scholar, theologian, logician and dialectician belonging to the Dvaita order of Vedanta. He served as the twentieth pontiff of Uttaradi Math from 1660 to 1673. He was a fiery and prolific writer and very ambitious of the glory of Dvaita Vedanta. He is considered to be one of the stalwarts in the history of the Dvaita school of thought, on account of his sound elucidations of the works of Madhvacharya, Jayatirtha and Vyasatirtha. Three of his polemically themed doxographical works (Abhinavamruta, Abhinava Chandrika and Abhinava Tarkatandava) are reminiscent of "Vyasatraya" (the three eyes of the man-lion of Madhva Siddhāntha). His refutation work Abhinava Gada is a devastating criticism of Appayya's Madhvamathamukhamardhana. His independent treatise Abhinava Chandrika is considered a brilliant work relating to the Brahma Sūtras, being a commentary on Jayatirtha's Tattvaprakashika. His work Abhinava Tarka Tandava refuted the works of rival systems, especially those of Prabhākara of Mimamsa, Ramanuja's Visistadvaita, and Gangesha Upadhyaya, Raghunatha Siromani of the Nyaya school, on the same lines as Vyasatirtha's Tarka Tandava. Indologist B.N.K.Sharma wrote, "His energy and determination to crush out the rivalry of Monism is reflected even in the choice of the titles of some of his works, four of which go by the name "Paraśus" (the Axe)".

Born into a family of scholars, Satyanatha Tirtha studied the six orthodox schools of Hinduism and subsequently, the philosophy of Dvaita under Satyanidhi Tirtha of Uttaradi Math, eventually succeeding him as the pontiff. B.N.K.Sharma wrote, "Satyanatha Tirtha made a bold pronouncement that women and Shudras are eligible for Aparokshajnana exclusively through shravana of Tantra". Sharma also wrote, "Satyanatha holds the memory of Vyasatirtha in warm admiration and refers him reverentially as Vyāsatīrthasrimaccaranah". He composed 12 works, consisting of commentaries on the works of Madhva, Jayatirtha and Vyasatirtha, and several independent treatises criticizing the tenets of contemporary schools, especially Advaita, while simultaneously elaborating upon the Dvaita thought. His dialectical skill and logical acumen is often compared with that of Vyasatirtha.

Information about Satyanatha Tirtha is derived from hagiographies: Satyanāthabhyudaya by Chalāri Saṁkarṣaṇacārya (a disciple of Satyabhinava Tirtha); Konkanabyudaya of Sagara Ramacharya and Sri Satyanatha Tirtharu (a biography in Kannada) by S.K. Badrinath. Indologist B.N.K.Sharma wrote, "His victorious career formed the subject of a eulogy by Chalāri Saṁkarṣaṇacārya, in his Satyanatha Mahatmya Ratnakara". Satyanatha Abhyudaya consists of eleven cantos and two manuscripts of this work are noticed by German Indologist Theodor Aufrecht which he quoted in his book Catalogus Catalogorum. B.N.K. Sharma opined the Satyanatha Abhyudaya is same as Satyanatha Mahatmya Ratnakara that was quoted in the Konkanabyudaya of Sagara Ramacharya. In Konkanabyudaya the author cited numerous Smritis and letters patent and bulls issued by Keladi rulers and pontiffs of some of the mutts at Udupi and of Satyabhinava Tirtha, Satyanatha Tirtha and others. The Alaṅkāramauktikamālā of Kṛṣṇa is another work which eulogises Satyanatha Tirtha.

B.N.K. Sharma says, Satyanatha Tirtha was originally named Narasimhacharya. He was born into an Kannada-speaking Deshastha Brahmin family of scholars in 1648 in Miraj, now in the southern part of Maharashtra. His father's name was Krishnacharya Avadhani and his mother's name was Rukmini Bai. Before becoming pontiff of the monastic institution Uttaradi Math, he was known by three names after taking Sannyasa. He was first ordained Sannyasa as an ordinary ascetic with the name Vidyanatha Tirtha by Krishnadwaipayana Tirtha (the disciple of Vedavyasa Tirtha), for second time he was named Ranganatha Tirtha by Dandaparivritti of Vedanidhi Tirtha and finally for the third time by Satyanidhi Tirtha, with the name Satyanatha Tirtha. In 1660 he took the seat of Uttaradi Math as the peetadhipathi, taking the name Satyanatha Tirtha.

According to the account in Sagara Ramacharya's Koñkanasthabhyudaya, Satyanatha Tirtha visited Benares at a time when Mughal emperor Aurangazeb was harassing the Hindus there. The same work says that he was a contemporary of Keladi Chennamma (queen of Keladi) and Aurangazeb. According to Sharma, it was presumably during this time that he visited Gaya and strengthened the hold of his mutt among the Gayapalas, who had been converted to Madhvism by his predecessor Vidyadhisha Tirtha. Satyanatha ordained sannyasa to Keshavacharya (the Purvashrama name of Satyabhinava Tirtha) in 1673. In the same year Satyabhinava Tirtha succeeded Satyanatha Tirtha as the pontiff of Uttaradi Math. After Satyanatha Tirtha died in 1674, his mortal remains were enshrined in the mutt at Veeracholapuram, a village in Tamil Nadu.

"He was a powerful and prolific writer and a noted controversialist in logic and theology."

Satyanatha Tirtha authored twelve works, consisting of polemical tracts, commentaries on the works of Madhva, Jayatirtha, independent works and a few hymns. The manuscripts are preserved in mutts at Veeracholapuram, Bangalore and Tirukoilur. Satyanatha wanted to emulate the example and philosophical work that had been accomplished by Vyasaraja. His work Abhinavamrita is a commentary on Jayatirtha's Pramana-Paddhati. Pramana-Paddhati is an epistemological work that discusses pramanas from the point of view of Dvaita Vedanta. His work Abhinavachandrika is composed on the same lines of Vyasatirtha's Tatparya Chandrika, which is a commentary on Jayatirtha's Tattvaprakasika, which apart from elucidating the concepts of the source text, criticises the allegations against Madhva raised by Appaya Dikshita and other grammarians. His work Abhinavatandava or Abhinavatarkatandava is polemical tract written on same lines of Vyasatirtha's Tarka Tandava. Satyanatha Tirtha also wrote glosses on the three Khandanas of Madhva. His commentaries on Dasaprakaranas texts are called Parasu, which is an indication of his intention to cut the opponents arguments to pieces. His works are referred as the Abhinava Granthas and Parashu Granthas.

Abhinava Chandrika is a well-known commentary on Jayatirtha's Tattva Prakasika, which in turn is a commentary on Madhva's Brahma Sutra Bhashya (which is a bhashya or a commentary on Badarayana's Brahma Sūtras). It is his magnum opus which runs to 12,500 stanzas. It is not in continuation of Tatparya Chandrika but an independent gloss, covering those portions (ch. I-II) commented upon by Vyasatirtha. Satyanatha refers in one of his introductory verses (no. 4) to Padmanabha Tirtha's Sattarkadipavali. 'In contrast to Vyasatirtha's Tatparya Chandrika, Satyanatha Tirtha here sets forth the Purvapaksha and Siddhanta views under each adhikarņa (or chapter), and offer criticisms on the former in accordance with the views of his teacher Satyanidhi Tirtha. B.N.K Sharma wrote, "His dextrous way of explaining the example of "Ahikundala" by constructing the term "vísesha" used by Jayatirtha in Tattvaprakasika in his twin senses of "visesa" and "bheda" is a masterstroke of resourcefulness".