Myles Dillon (11 May 1900 — 18 June 1972) was an Irish historian, philologist and celticist.
Myles Dillon was born in Dublin; he was one of six children of John Dillon and his wife Elizabeth Mathew; James Matthew Dillon, the leader of Fine Gael, was his younger brother.
Myles Dillon graduated from University College Dublin, than travelled to Germany and France, where he studied in deep Old Irish and Celtic philology under Joseph Vendryes and Rudolf Thurneysen. Dillon taught Sanskrit and comparative philology in Trinity College, Dublin (1928–1930) and University College, Dublin (1930–1937). In 1937 moved to USA, where he taught Irish in the University of Madison (his son John M. Dillon was born in Madison), in 1946-1947 taught in Chicago. On his return to Ireland worked in the School of Celtic Studies in Dublin Institute for Advanced Studies; was the director of the School from 1960 till 1968, edited Celtica. Volume 11 of Celtica is dedicated to his memory.
Myles Dillon is the author of a number of important scholarly books, handbooks and translations from Old Irish. Among his most notable works are The Cycles of the Kings (1946), Early Irish literature (1948), The Celtic realms (1967, with Nora Kershaw Chadwick). M. Dillon published a modern translation and commentary of The Book of Rights (Old Irish: Lebor na cert, 1962). He also translated Dieux et héros des Celtes by Marie-Louise Sjoestedt into English, thus making the book available for a wider scholarly audience. The monograph Celts and Aryans, published posthumously by the Indian Institute of Advanced Study reflects Dillon's interest in the traces of the shared heritage in the Indian and Irish cultures deriving from Proto-Indo-European society based on a period of research Dillon spent in Simla, India.