3rd-century BC writers

thumb| Berossus () or Berosus (; ; possibly derived from ) was an early-3rd-century BCE Hellenistic-era Babylonian writer, priest of Bel Marduk, and astronomer who wrote in the Koine Greek language.

Kātyāyana (कात्यायन) also spelled as Katyayana ( century BCE) was a Sanskrit grammarian, mathematician and Vedic priest who lived in ancient India.

Vararuci (also transliterated as Vararuchi) () is a name associated with several literary and scientific texts in Sanskrit and also with various legends in several parts of India. This Vararuci is often identified with Kātyāyana. Kātyāyana is the author of Vārtikās which is an elaboration of certain sūtrās (rules or aphorisms) in Pāṇini's much revered treatise on Sanskrit grammar titled Aṣṭādhyāyī. Kātyāyana is believed to have flourished in the 3rd century BCE. However, this identification of Vararuci with Kātyāyana has not been fully accepted by scholars. Vararuci is believed to be the autho