Bhartṛhari (Devanagari: भर्तृहरि; Bhartrihari; fl. c. 5th century CE), was an Indian-Hindu linguistic philosopher and poet, known for his contributions to the fields of linguistics, grammar, and philosophy. He is believed to have been born in the 5th century in Ujjain, Malwa, India. He decided to live a monastic life and find a higher meaning but was unable to detach from worldly life. He lived as a yogi in Ujjain until his death.

He is best known for his works, the Vākyapadīya (a treatise on sentences and words), Mahābhāṣyatikā (a commentary on Patanjali's Mahabhashya), Vākyapadīyavṛtti (a commentary on Vākyapadīya kāṇḍas 1 and 2), Śabdadhātusamīkṣā, and the 300-verse collection Śatakatraya.

Bhartrhari's philosophy is marked by the concept of "Shabda-Brahman", that the ultimate reality is expressed through words. He posited that language and cognition are linked and that by understanding grammar one can attain spiritual liberation.

Bhartrhari's works have been studied in various Indian philosophical traditions, including Vedanta and Mimamsa. Islamic and Western scholars have also shown interest through various translations and commentaries. In the field of Indian poetics, Bhartrhari's Śatakatraya continues to be revered and studied and has been translated into many languages, affording access to a global audience.

Bhartrhari is believed to have been born in Ujjain, Malwa, India and lived in the 5th century. Details of his personal life are not known, but it is assumed, and accepted by scholars, that he lived between 485 and 540 CE. He was associated with the court of Valabhi (modern Vala, Gujarat) but decided to follow the path of Indian sages and renounced a sensual life to find higher meaning. He attempted to live a monastic life but was unable to successfully detach from worldly pleasures. After some time, he lived a life as a yogi in Ujjain till his death.

Siṃhasūrigaṇi, a 6th-century Jain writer, states that Bhartrhari studied under a grammarian named Vasurāta. Bhartrhari credits some of his theories to Vasurāta in his work the Vakyapadiya.

The Chinese traveller Yi-Jing (635-713 CE) mentions Bhartrhari in his travel notes. He claims that Bhartrhari was a Buddhist and wrote the works Vakyapadiya, Peina, and a commentary on Patanjali's Mahabhashya. Researchers have found some of the details given by Yi-Jing to be erroneous, specifically the time period that he was alive and that he was a Buddhist. Bhartrhari's philosophical position is widely held to be an offshoot of the Vyākaraṇa or grammarian school, closely allied to the realism of the Nyayas and distinctly opposed to Buddhist positions such as those of Dignaga, who was closer to phenomenalism.

Bhartrhari is known for his work in the philosophy of language, particularly his theories articulated in the Vākyapadīya ("Treatise on Sentences and Words"). This text is a comprehensive study of grammar and its metaphysical foundations. Bhartrhari's philosophy is marked by the concept of "Shabda-Brahman", which holds that the ultimate reality is expressed through words. He posited that language and cognition are linked and that by understanding grammar one can attain spiritual liberation.