Scottish lexicographer and first editor (from 1879) of A New English Dictionary on Historical Principles, now known as The Oxford English Dictionary (Oxford English Dictionary, The). He was knighted in 1908.

Murray was a grammar-school teacher from 1855 to 1885, during which time he also wrote a famous article on the English language for Encyclopædia Britannica (1878) and served as president of the Philological Society (1878–80, 1882–84). He undertook the editing of a vast dictionary that was intended as an inventory of words used in English from the mid-12th century and, in some instances, from earlier dates. Construction of the dictionary was to be grounded on strict historical and descriptive principles, and each definition was to be accompanied by an example, including date, of usage. The first section, A–Ant, appeared in 1884, printed at the Clarendon Press, Oxford. From 1885 until his death, Murray lived at Oxford, working with a staggering volume of materials and completing about half of the dictionary, sections A–D, H–K, O, P, and T. It was his organization that made completion of the great undertaking possible.