Epigraphy (from Ancient Greek ἐπιγραφή (epigraphḗ) 'inscription') is the study of inscriptions, or epigraphs, as writing; it is the science of identifying graphemes, clarifying their meanings, classifying their uses according to dates and cultural contexts, and drawing conclusions about the writing and the writers. Specifically excluded from epigraphy are the historical significance of an epigraph as a document and the artistic value of a literary composition. A person using the methods of epigraphy is called an epigrapher or epigraphist. For example, the Behistun inscription is an official document of the Achaemenid Empire engraved on native rock at a location in Iran. Epigraphists are responsible for reconstructing, translating, and dating the trilingual inscription and finding any relevant circumstances. It is the work of historians, however, to determine and interpret the events recorded by the inscription as document. Often, epigraphy and history are competences practised by the same person. Epigraphy is a primary tool of archaeology when dealing with literate cultures. The US Library of Congress classifies epigraphy as one of the auxiliary sciences of history. Epigraphy also helps identify a forgery: epigraphic evidence formed part of the discussion concerning the James Ossuary.

An epigraph (not to be confused with epigram) is any sort of text, from a single grapheme (such as marks on a pot that abbreviate the name of the merchant who shipped commodities in the pot) to a lengthy document (such as a treatise, a work of literature, or a hagiographic inscription). Epigraphy overlaps other competences such as numismatics or palaeography. When compared to books, most inscriptions are short. The media and the forms of the graphemes are diverse: engravings in stone or metal, scratches on rock, impressions in wax, embossing on cast metal, cameo or intaglio on precious stones, painting on ceramic or in fresco. Typically the material is durable, but the durability might be an accident of circumstance, such as the baking of a clay tablet in a conflagration.

The character of the writing, the subject of epigraphy, is a matter quite separate from the nature of the text, which is studied in itself. Texts inscribed in stone are usually for public view and so they are essentially different from the written texts of each culture. Not all inscribed texts are public, however: in Mycenaean Greece the deciphered texts of "Linear B" were revealed to be largely used for economic and administrative record keeping. Informal inscribed texts are "graffiti" in its original sense.

The study of ideographic inscriptions, that is inscriptions representing an idea or concept, may also be called ideography. The German equivalent Sinnbildforschung was a scientific discipline in the Third Reich, but was later dismissed as being highly ideological. Epigraphic research overlaps with the study of petroglyphs, which deals with specimens of pictographic, ideographic and logographic writing. The study of ancient handwriting, usually in ink, is a separate field, palaeography. Epigraphy also differs from iconography, as it confines itself to meaningful symbols containing messages, rather than dealing with images.