Clackson is Reader in Comparative Philology at the Faculty of Classics, University of Cambridge, and is also a Fellow and Director of Studies, Jesus College at Cambridge. He was awarded a Philip Leverhulme Prize in 2001. He is currently the editor of the Transactions of the Philological Society, the oldest scholarly journal devoted to the study of language that has an unbroken tradition.
Clackson studied at Cambridge under Robert Coleman; his Ph.D. thesis served as a basis for his 1994 book The Linguistic Relationship between Armenian and Greek. His research interest include ancient Languages of the Italian peninsula (Latin, Sabellian, Etruscan), Indo-European linguistics, Latin linguistics, Greek linguistics and Armenian.