The Archimedes Palimpsest is a parchment codex palimpsest, originally a Byzantine Greek copy of a compilation of Archimedes and other authors. It contains two works of Archimedes that were thought to have been lost and the only surviving original Greek edition of his work On Floating Bodies. The first version of the compilation is believed to have been produced by Isidorus of Miletus, the architect of the geometrically complex Hagia Sophia cathedral in Constantinople, sometime around AD 530. The copy found in the palimpsest was created from this original, also in Constantinople, during the Macedonian Renaissance, a time when mathematics in the capital was being revived by the former Greek Orthodox bishop of Thessaloniki Leo the Geometer, a cousin of the Patriarch.

In textual studies, a palimpsest is a manuscript page, either from a scroll or a book, from which the text has been scraped or washed off in preparation for reuse in the form of another document. Parchment was made of lamb, calf, or kid skin and was expensive and not readily available, so, in the interest of economy, a page was often re-used by scraping off the previous writing. In colloquial usage, the term palimpsest is also used in architecture, archaeology and geomorphology to denote an object made or worked upon for one purpose and later reused for another; for example, a monumental brass the reverse blank side of which has been re-engraved.