Yiddish theatre consists of plays written and performed primarily by Jews in Yiddish, the language of the Central European Ashkenazi Jewish community. The range of Yiddish theatre is broad: operetta, musical comedy, and satiric or nostalgic revues; melodrama; naturalist drama; expressionist and modernist plays. At its height, its geographical scope was comparably broad: from the late 19th century until just before World War II, professional Yiddish theatre could be found throughout the heavily Jewish areas of Eastern and East Central Europe, but also in Berlin, London, Paris, Buenos Aires and New York City.

Yiddish is a West Germanic language historically spoken by Ashkenazi Jews. It originates from 9th century Central Europe, providing the nascent Ashkenazi community with a vernacular based on High German fused with many elements taken from Hebrew and to some extent Aramaic. Most varieties of Yiddish include elements of Slavic languages and the vocabulary contains traces of Romance languages. Yiddish has traditionally been written using the Hebrew alphabet; however, there are variations, including the standardized YIVO orthography that employs the Latin alphabet.