Eduard Rudolf Thurneysen (14 March 1857 – 9 August 1940) was a Swiss linguist and Celticist.

[1] He received his promotion (approximating to a doctorate) in 1879 and his habilitation, in Latin and the Celtic languages, followed at the University of Jena in 1882.

From 1885 to 1887 he taught Latin at Jena, then taking up the Chair of Comparative Philology at the University of Freiburg[1] where he replaced Karl Brugmann, a renowned expert in Indo-European studies.

[2] In 1909 Thurneysen published his Handbuch des Alt-Irischen, translated into English as A Grammar of Old Irish by D. A. Binchy and Osborn Bergin, and still in print as of 2006.

[1] A version in Welsh was produced by Melville Richards and published by Gwasg Prifysgol Cymru (University of Wales Press) in 1935 under the title Llawlyfr Hen Wyddeleg.