Dymer is a narrative poem by C. S. Lewis (published by J. M. Dent) in 1926 under the pseudonym Clive Hamilton (his actual first name followed by his mother's maiden name). Lewis worked on this poem, his most important poem, as early as 1916, when still only 17 years old, and completed it in 1925. It was Lewis's second published work.
He thought of himself writing in the tradition of Homer, Milton, Spenser, Wordsworth, and others. George Sayer's analysis suggests that the book is about the temptation of fantasies, "the fantasies of love, lust, and power."