John Rupert Firth (1890, Keighley, Yorkshire – 1960, Lindfield, Sussex) was Britain’s first Professor of Linguistics. He was an important figure in the foundation of linguistics as an individual discipline in his home country and is known for his original ideas on phonology and the study of meaning.

Firth held positions at the University of the Punjab (1920-1928), University College London (1928-1938) and the School of Oriental and African Studies, SOAS (1938-1956). During his time in London, Firth influenced a generation of British linguists and the popularity of his ideas gave rise to what is known as the “London School” of linguistics, which included, among others, W.S. Allen, Jack Carnochan, Eugénie Henderson, R.H. Robins, R.K. Sprigg and Eileen Whitley.

Firth’s main contribution to linguistics is considered to be Prosodic Phonology, which he saw as radically different from phonemic theory. His concept of prosody prefigures later work in autosegmental phonology. Prosodic Phonology treats syntagmatic and paradigmatic relations as of equal importance; Firth saw phonemic phonology as one which emphasised paradigmatic relations at the expense of syntagmatic ones. The two main units of analysis are phonematic units and prosodies. Other distinguishing features of Firth's phonology are that it separates phonetics strictly from phonology; it is polysystemic; and it places grammar at the heart of analysis.

Firth also drew attention to the context-dependent nature of meaning with his notion of ‘context of situation’.

The Archive contains an almost complete collection of Firth’s work, notes on his lectures, letters from Firth, and a few papers with Firth's marginal notes.