Stephanos Matthaios studied Classics at the National and Kapodistrian University of Athens (BA 1988) and completed his postgraduate studies in Classics and Linguistics at the University of Göttingen (PhD in Classics 1998). He worked as research assistant at the Department of Classics of the University of Cologne (1998-2000), as Lecturer and Assistant Professor of Ancient Greek Literature at the University of Cyprus (2000-2006) and as Assistant Professor at the Department of Classics of Aristotle University of Thessaloniki (2006-2018). Since 2018 he is Associate Professor of Ancient Greek Literature at the Department of Classical Studies, School of Philosophy, Faculty of Philology at the National and Kapodistrian University of Athens. During SS 2010 he taught as visitor lecturer at the Department of Classics of the University of Freiburg, while in SS 2014 he taught as Spinoza visiting fellow at the Classics Department of the University of Leiden. His research interests include ancient linguistics, ancient and Byzantine lexicography, ancient scholia and commentaries, especially Homeric scholarship in antiquity, Eratosthenes and the Hellenistic science as well as the history of the Greek language. He has been a member of editorial board of the Journal of Greek Linguistics and of the Göttinger Beiträge zur Sprachwissenschaft. Since 2018 he is member of the International Scientific Committee of the journal Histoire Epistémologie Langage. He is also member of the Society 'Studienkreis Geschichte der Sprachwissenschaft (SGdS)'.
He is the author of the book Untersuchungen zur Grammatik Aristarchs: Texte und Interpretation zur Wortartenlehre (Hypomnemata 126, Göttingen 1999) and of numerous articles on ancient linguistics, ancient and Byzantine lexicography, Hellenistic scholarship (esp. Homeric scholarship) and scholarship and erudition in the Imperial period and during Late Antiquity. He is co-editor and co-author of the following volumes: (1) Linguistische und epistemologische Konzepte - diachron (ed. with P. Schmitter; Münster 2007), (2) Das Adverb in der Grammatikographie (ed. with A. Kärnä; 2 vols., Münster 2007-08), (3) Ancient Scholarship and Grammar. Archetypes, Concepts and Contexts (ed. with F. Montanari and A. Rengakos; Berlin - New York 2011) and (4) Brill's Companion to Ancient Greek Scholarship (ed. with F. Montanari and A. Rengakos; 2 vols, Leiden - Boston 2015). He is associate editor of the Encyclopedia of Ancient Greek Language and Linguistics (EAGLL) (General editor: G.K. Giannakis; 3 vols, Leiden - Boston 2014). He has cooperated with Helmut van Thiel (University of Cologne) on the edition of the Scholia of Pseudo-Didymus on the Iliad (Scholia D in Iliadem. Proecdosis 2000).