The Hypnerotomachia Poliphili (in Greek, Poliphilo's Strife of Love in a Dream), first printed during the Renaissance, is known as an unusual book in history.

The book was printed by Aldus Manutius in Venice in December 1499. The book is anonymous, but an acrostic formed by the first, elaborately decorated letter in each chapter in the original Italian reads POLIAM FRATER FRANCISCVS COLVMNA PERAMAVIT, "Brother Francesco Colonna dearly loved Polia." However, the book has also been attributed to Leon Battista Alberti by several scholars, and earlier, to Lorenzo de Medici. The latest contribution in this respect was the attribution to Aldus Manutius.

The text of the book is written in a bizarre Latinate Italian, full of words coined based on Latin and Greek roots without explanation. The book, however, also includes words from the Italian language, as well as illustrations including Arabic and Hebrew words; Colonna also invented new languages when the ones available to him were inaccurate. (It also contains some uses of Egyptian hieroglyphs, but they are not authentic.) Its story, which is set in 1467, consists of precious and elaborate descriptions of scenes involving the title character, Poliphilo ("Lover of Many Things", from Greek Polú "Many" + Philos "Beloved"), as he wanders a sort of bucolic-classical dreamland in search of his love Polia ("Many Things"). The author's style is elaborately descriptive and unsparing in its use of superlatives.

The book has long been sought after as one of the most beautiful incunabula ever printed. The typography is famous for its quality and clarity, in a typeface cut by Francesco Griffo. The book is illustrated with 174 exquisite woodcuts showing the scenery, architectural settings, and some of the characters Poliphilo encounters in his dreams. The illustrations are perhaps the best part of the book; delicate and evocative, they depict scenes from Poliphilo's adventures, or the architectural features over which the text rhapsodizes, in a simultaneously stark and ornate line art style which perfectly integrates with the type. These images are also interesting because they shed light on what people in the Renaissance fancied about the alleged æsthetic qualities of Greek and Roman antiquities.

The psychologist Carl Jung admired the book, believing the dream images presaged his theory of archetypes. The style of the woodcut illustrations had a great influence on late-19th century English illustrators, such as Aubrey Beardsley, Walter Crane and Anning Bell.

Hypnerotomachia Poliphili was partially translated into English in a London edition of 1592 by "R. D.", believed to be Robert Dallington, who gave it the title by which it is best known in English, The Strife of Love in a Dream. A facsimile of this edition can be seen online at the Internet Archive.

The first complete English version was published by Thames & Hudson in 1999, five hundred years after the original. Hypnerotomachia Poliphili, the Strife of Love in a Dream was translated by musicologist Joscelyn Godwin and typeset in Monotype Corporation's typeface "Poliphilus", a re-creation of Griffo's original. A smaller format paperback edition was published in February 2005. However, probably due to the difficulty of the original, the translation is recreated in standard, modern language, rather than following the original's pattern of coining and borrowing words; for this reason, the translation may be of interest to those curious to learn more about the Hypnerotomachia, but it will probably not be useful for serious scholars.