Hans Blumenfeld (1892–1988), former Deputy Director of the Metropolitan Toronto Planning Board — one of the first institutions of its kind in North America — produced an important body of historical and theoretical work aimed at understanding metropolization as the contemporary form of urbanization and as a new kind of dominant landscape. Using North American cities — most notably Toronto — as case studies, he analyzed shifting socio-economic, productive, and anthropological structures, as well as the spatial and architectural forms that emerged from them. Despite the significance of his theoretical legacy, Blumenfeld’s life and work remain largely overlooked. This paper seeks to retrace his intellectual and professional trajectory — from Germany in the 1910s and 1920s, through Red Vienna and the USSR of the 1930s, to North America in the 1940s — in order to illuminate a crucial chapter in the history of planning thought and aesthetic interpretations of the modern metropolis, situated within the political and ideological struggles that shaped them.