This thesis is the first study of the Yiddish theatre in London during and after the Second World War, analysing the mission, repertoire, reception, and success of the Naye yidishe teater (New Yiddish Theatre). Established in 1943 in London in the midst of the war and with growing awareness of the atrocities on the continent, the company was born out of Jewish cultural nationalist thought, and was a renewed attempt to create a modern, secular Yiddish culture in London in the wake of Nazi persecution and the Holocaust. This thesis explores the ways in which this unique context inspired and shaped the mission, repertoire, and success of the New Yiddish Theatre Company, arguing that the theatre characterised both the transnational nature of theatrical exchange while still being shaped and influenced by the unique circumstances of its host nation. It also situates the New Yiddish Theatre Company as a late iteration of cultural nationalism, revived by the ever-growing reality of the great loss of Yiddish cultural life across Europe. Entwining the histories of Anglo-Jewry, Yiddish culture, and Jewish life and identity in the 1940s, this thesis brings together a range of Yiddish and English language sources to demonstrate not only the importance of the New Yiddish Theatre project in the history of global Yiddish theatre but the impact it had on the unique Anglo-Jewish context in which it emerged. It argues that the New Yiddish Theatre project was one of great ambition and posits as part of a small but vibrant Yiddish cultural scene that was active yet fragmented. It goes on to demonstrate, however, that despite the commitment of its founders and ambition of their endeavour, the New Yiddish Theatre was not able to achieve its mission, a result of not only the broader decline of global Yiddish culture but the unique circumstances that Jewish life in Britain presented.