Patañjali (Sanskrit: पतञ्जलि) is a proper Indian name. Several important ancient Sanskrit works are ascribed to one or more authors of this name, and a great deal of scholarship has been devoted over the last century or so to the issue of disambiguation.
Amongst the more important authors called Patañjali are:
According to Monier Monier-Williams, the word "Patañjali" is a compound name from "patta" (Sanskrit: पत, "falling, flying") and "añj" (अञ्ज्, "honor, celebrate, beautiful") or "añjali" (अञ्जलि, "reverence, joining palms of the hand").
Louis Renou was among the many scholars who have suggested that the Patañjali who wrote on Yoga was a different person than the Patanjali who wrote a commentary on Panini's grammar. In 1914, James Wood proposed that they were the same person. In 1922, Surendranath Dasgupta presented a series of arguments to tentatively propose that the famed Grammar text and the Yoga text author may be identical.
The view that these were likely two different authors is generally accepted, but some Western scholars consider them as same.
Some in the Indian tradition have held that one Patañjali wrote treatises on grammar, medicine and yoga. This has been memorialised in a verse by Bhoja at the start of his commentary on the Yogasutras called Rājamārttanda (11th century), and the following verse found in Shivarama's 18th-century text:
योगेन चित्तस्य पदेन वाचां मलं शरीरस्य च वैद्यकेन। योपाकरोत्तं प्रवरं मुनीनां पतञ्जलिं प्राञ्जलिरानतोस्मि॥
English translation: I bow with my hands together to the eminent sage Patañjali, who removed the impurities of the mind through yoga, of speech through grammar, and of the body through medicine.
This tradition is discussed by Meulenbeld who traces this "relatively late" idea back to Bhoja (11th century), who was perhaps influenced by a verse by Bhartṛhari (ca. 5th century) that speaks of an expert in yoga, medicine and grammar who, however, is not named. No known Sanskrit text prior to the 10th century states that the one and the same Patanjali was behind all the three treatises.