This article examines architecture designed and built by the Canadian Broadcasting Corporation/ Radio-Canada (CBC) from 1940-1953. Following the Second World War, the construction of buildings across the country confirmed and solidified the Crown Corporation’s position as a national service, reinforcing social democratic values held by cultural elites. These buildings became important material components of radio publics as they amplified the public broadcaster’s presence. Focussing on transmission stations and studios, the article shows how the building of radio infrastructure strategically promoted a sense of national community on the one hand yet tapped into regionalism on the other. The article illuminates the overlooked material presence of radio and adds to recent scholarly interest in studying media houses by arguing that the architecture of radio was instrumental in the composition of modern, mediated publics in the mid-twentieth century.