In this essay Paul Maloney and Adrienne Scullion investigate the ambitious agenda of theatre internationalism in the context of non-professional theatre making in Glasgow in the mid-twentieth century. For members of the Glasgow Jewish Institute Players, internationalism was represented through a diverse repertoire of classic European texts and contemporary American plays, presented alongside new original plays and sketches drawing on Yiddish and Scottish popular theatre tropes, and experienced through its members’ range of international diasporic networks, specifically with Jewish theatre makers in New York. It is argued that the internationalizing experience of the company and, specifically, its sustained exploration of immigration and of immigrants, achieves an important, even defining, role in the formation of a modern theatre industry and identity in Scotland. Historically interesting in and of itself, this article is also timely given a wider social and cultural ‘fear’ of contemporary migrants. The research encompasses a range of previously unexplored primary material including scripts, reviews, photographs, and company papers, including correspondence with New York-based playwright Sylvia Regan and new interviews with surviving company members. Paul Maloney and Adrienne Scullion work at Queen's University Belfast.