Dionysius Thrax (Greek: Διονύσιος ὁ Θρᾷξ, Ancient: [di.o.ný.si.os ho tʰrâːiks], Contemporary Koine: [djoˈny.sjos ho ˈtʰraks]; 170–90 BC) was a Hellenistic grammarian and a pupil of Aristarchus of Samothrace. His place of origin was not Thrace as the epithet "Thrax" denotes, but probably Alexandria (his father's descent was Thracian). He lived and worked in this city but later taught at Rhodes.
The first extant grammar of Greek, Art of Grammar (Τέχνη γραμματική Tékhnē grammatiké) is attributed to him but many scholars today doubt that the work really belongs solely to him due to the difference between the technical approach of most of the work and the more literary approach (similar to the 2nd century's Alexandrian tradition) of the first few sections. It concerns itself primarily with a morphological description of Greek, lacking any treatment of syntax. The work was translated into Armenian and Syriac in the early Christian era.
Thrax defines grammar at the beginning of the Tékhnē as "the practical knowledge of the general usages of poets and prose writers." Thus Dionysius Thrax, like contemporary Alexandrian scholars who edited Attic Greek and Homeric texts, was concerned with facilitating the teaching of classic Greek literature to an audience who spoke Koine Greek.
- There are extensive scholia to the Techne, which have been edited by A. Hilgard in 1901: Scholia in Dionysii Thracis Artem Grammaticam, recensuit et apparatum criticum indicesque adiecit Alfredus Hilgard, Lipsiae: in aedibus B.G. Teubneri 1901. The collections of scholia are the following: Prolegomena Vossiana (p.1); Commentarius Melampodis seu Diomedis (p. 10); Commentarius Heliodori (p. 67); Scholiorum collectio Vaticana (p. 106); Scholiorum collectio Marciana (p. 292); Scholiorum collectio Londinensis (p. 442); Commentariolus Byzantinus (pp. 565–586).
- The Tekhne Grammatike of Dionysius Thrax Translated into English by J. Alan Kemp (Historiographia Linguistica 13:2/3, 1986, pp. 343–363).
- Robins, R. H. A Short History of Linguistics (Indiana UP, 1967). (ISBN 0-253-35210-X)
- Robins, R. H. The Technē Grammatikē of Dionysius Thrax in historical perspective. In P. Swiggers, W. van Hoecke (Eds.), Mots et parties du discours. Leuven: Leuven University Press, 1987.
- Vincenzo Di Benedetto, "At the Origins of Greek Grammar," Glotta 68 (1990): 19–39.
- Vivien Law, Ineke Sluiter (eds.), Dionysius Thrax and the Techne grammatike Münster: Nodus Publikationen, 1995.
- J. Lallot, La grammaire de Denys le Thrace, Paris: CNRS Éditions, 1998 (2e édition 2003).