Sir Denys Lionel Page FBA (11 May 1908 – 6 July 1978) was a British classicist and textual critic who served as the 34th Regius Professor of Greek at the University of Cambridge and the 35th Master of Jesus College, Cambridge. He is best known for his critical editions of the Ancient Greek lyric poets and tragedians.

Coming from a middle-class family in Reading, Page studied classics at Christ Church, Oxford, and served the college as a lecturer for most of the 1930s. He spent the Second World War working on Ultra intelligence material at the Government Code and Cypher School based at Bletchley Park. In 1950, he was elected Regius Chair of Greek at Cambridge which he held until his retirement in 1973. Initially a fellow of Trinity College, Cambridge, Page was appointed master of the university's Jesus College in 1959. He died of lung cancer in 1978.

Having published an edition of the poets Sappho and Alcaeus with fellow Oxford classicist Edgar Lobel, Page went on to write what became for some time the standard edition of the remaining Greek lyric poets, Poetae Melici Graeci (PMG, 1962). His other notable publications include commentaries on Euripides' Medea (1938) and Aeschylus' Agamemnon (1957). In 1971, he was knighted for his services to classical scholarship.

Denys Lionel Page was born on 11 May 1908 in Reading, Berkshire, to Frederick Page, a railway engineer at the Great Western Railway and his wife Elsie. He spent part of his childhood in South Wales but returned to Berkshire and became a student at Newbury Grammar School.

In 1926, he won a scholarship to study classics at Christ Church, Oxford. Although Page came from a modest background compared to most of his peers, he settled in well at the college and made a number of friends, including the future Lord Chancellor Quintin Hogg and the Labour politician Patrick Gordon Walker. Among his tutors at Oxford, the archaeologist John Beazley and the Hellenist John Dewar Denniston exerted the greatest influence on his future work. He graduated with a Bachelor of Arts in 1930 and was awarded a Derby Scholarship. The award enabled him to spend a year at the University of Vienna with the German philologist Ludwig Radermacher.

In 1931, Page was appointed a lecturer at Christ Church and became a Student (a full member of the college's governing body) the following year. It was during this period that he began working on the plays of the Greek poet Euripides, which culminated in the publication of a critical edition and commentary of Euripides' Medea (1938). Following in the footsteps of fellow Oxford classicist Edgar Lobel, he also worked on the poems of the archaic Greek lyric poets.

Page assumed an active role in college affairs. In 1936, he strongly opposed the candidacy of the Irish scholar E. R. Dodds for the Regius Chair of Greek which was hosted at Christ Church. Dodds was elected to the position in spite of Page's reservations. In 1937 he was appointed to the office of junior censor at the college – the Censor Naturalis Philosophiae, responsible for undergraduate discipline. However, he resigned the position a year later to marry Katharine Elizabeth Dohan, daughter of the American archaeologist Edith Hall Dohan. They had four daughters, one of whom is the Assyriologist Stephanie Dalley. In 1939, he briefly served as the inaugural Andrew Fleming West Professor in Classics at Princeton University.

In 1939, Page was recruited to the Government Code and Cypher School and posted to Bletchley Park. Page's command of German, acquired during his time at Vienna, was put to use in the interpretation activities of Hut 9A. In 1942 he joined the ISOS "illicit signals" section run by Oliver Strachey and later headed that unit. In this role, he joined the inter-services XX Committee, and became a Deputy Director of GC&CS. After the end of World War II in Europe, he was part of a mission to the British headquarters in Colombo, then Singapore and finally Sri Lanka near the end of the war.