John Ronald Reuel Tolkien (1892-1973) was a major scholar of the English language, specialising in Old and Middle English. Twice Professor of Anglo-Saxon (Old English) at the University of Oxford, he also wrote a number of stories, including most famously The Hobbit (1937) and The Lord of the Rings (1954-1955), which are set in a pre-historic era in an invented version of the world which he called by the Middle English name of Middle-earth. This was peopled by Men (and women), Elves, Dwarves, Trolls, Orcs (or Goblins) and of course Hobbits. He has regularly been condemned by the English Literature establishment, with honourable exceptions, but loved by literally millions of readers worldwide.

In the 1960s, he was taken up by many members of the nascent "counter-culture" largely because of his concern with environmental issues. In 1997, he came top of three British polls, organised respectively by Channel 4 / Waterstone's, the Folio Society, and SFX, the UK's leading science fiction media magazine, amongst discerning readers asked to vote for the greatest book of the 20th century.

From 1925 to 1945, Tolkien was the Rawlinson and Bosworth Professor of Anglo-Saxon and a Fellow of Pembroke College, both at the University of Oxford. He then moved within the same university to become the Merton Professor of English Language and Literature and Fellow of Merton College, and held these positions from 1945 until his retirement in 1959. Tolkien was a close friend of C. S. Lewis, a co-member of the informal literary discussion group The Inklings. He was appointed a Commander of the Order of the British Empire by Queen Elizabeth II on 28 March 1972.

After Tolkien's death, his son Christopher published a series of works based on his father's extensive notes and unpublished manuscripts, including The Silmarillion. These, together with The Hobbit and The Lord of the Rings, form a connected body of tales, poems, fictional histories, invented languages, and literary essays about a fantasy world called Arda and, within it, Middle-earth. Between 1951 and 1955, Tolkien applied the term legendarium to the larger part of these writings.

While many other authors had published works of fantasy before Tolkien, the great success of The Hobbit and The Lord of the Rings led directly to a popular resurgence of the genre. As a result, he has been popularly identified as the "father" of modern fantasy literature—or, more precisely, of high fantasy, and is widely regarded as one of the most influential authors of all time.