Judeo-Latin (also spelled Judaeo-Latin) is the use by Jews of the Hebrew alphabet to write Latin.^[2] The term was coined by Cecil Roth to describe a small corpus of texts from the Middle Ages.^[2] In the Middle Ages, there was no Judeo-Latin in the sense of "an ethnodialect used by Jews on a regular basis to communicate among themselves", and the existence of such a Jewish language under the Roman Empire is pure conjecture.^[3]

The Judeo-Latin corpus consists of an Anglo-Jewish charter and Latin quotations in otherwise Hebrew works (such as anti-Christian polemics,^[4] incantations and prayers).^[2] Christian converts to Judaism sometimes brought with them an extensive knowledge of the Vulgate translation of the Bible. The Sefer Nizzahon Yashan and Joseph ben Nathan Official's Sefer Yosef ha-Mekanne contain extensive quotations from the Vulgate in Hebrew letters.^[2] Latin technical terms sometimes appear in Hebrew texts.^[2] There is evidence of the oral use of Latin formulas in dowsing, ordeals and ceremonies.^[2]

Leo Levi found some Hebraisms in a few epigraphs in Italy.^[5]