| Geoffrey Lewis | |
| Birth Name: | Geoffrey Lewis Lewis |
| Birth Date: | 19 June 1920 |
| Birth Place: | London, England |
| Death Place: | Summertown, Oxford, England |
| Occupation: | Turkologist |
| Children: | 2 |
| Education: | St John's College, Oxford (BA, DPhil) |
| Thesis Title: | "A re-examination of the so-called theology of Aristotle" |
| Thesis Year: | 1950 |
| Academic Advisors: | H. A. R. Gibb |
| Notable Works: | Turkish Grammar (1967) |
Geoffrey Lewis Lewis (19 June 1920 – 12 February 2008) was an English Turkologist and the first Professor of Turkish at the University of Oxford. He is known as the author of Teach Yourself Turkish and academic books about Turkish and Turkey.
Lewis was born in London in 1920 and educated at University College School and St John's College, Oxford (MA 1945, DPhil 1950; James Mew Arabic Scholar, 1947).
At St John's College Lewis initially studied Classics. With the outbreak of the Second World War, he served from 1940 to 1945 as a radar operator in the Royal Air Force. Posted primarily in Libya and Egypt, he taught himself Turkish through local Turkish acquaintances, from the Turkish newspaper Yedi Gün available in Cairo, and from Turkish translations of English classics sent to him by his wife. He returned to Oxford in 1945 with his newly acquired interest in Turkish and on the advice of H. A. R. Gibb took a second BA degree in Arabic and Persian as groundwork for Ottoman Turkish, which he finished with first-class honours (not achieved in this double subject since Anthony Eden in 1922) in just two years. He spent six months in Turkey before pursuing his doctoral work on a medieval Arabic philosophical treatise at St John's College.
Turkish was not taught at Oxford before Lewis was appointed to his academic post in 1950; it was through his efforts that it became established in the Oxford syllabus of Oriental studies by 1964.
He was appointed to the chair of Turkish in 1986. He retired in 1987 and was succeeded in the following year by Celia Kerslake.