Abstract: In Western countries, the discipline of interior design has struggled to define itself from the beginning. One reason is that designing interiors is a multifaceted, layered, even interdisciplinary process. One has to deal with architectural environments as well as objects, with spaces as well as more ephemeral backdrops. Moreover, because designing interiors is not very different from certain everyday activities, interior professionals want to dissociate their activities from everyday decorating. Nomenclature has played an important role in trying to professionalize. By employing the term of interior architect, professional practitioners have sought to insist on the distance that separates their work from everyday design practices. However, interior architecture has also wanted to avoid being seen as a subcategory of architecture. As a result, alternative terms have circulated, which have been equally question-begging. By means of a case study of one country's attempt to professionalize the practice of designing interiors, this essay will uncover how professional identities emerged and were labeled in postwar Belgian Flanders. We will show how different profiles, ranging from schooled interior architects to self-made domestic advisors and interior decorators, enabled practitioners to approach interiors differently and sometimes design in different ways. At the same time, we will investigate why the term Interior architect was employed by all the profiles of practitioners. The historically and culturally specific case study will be framed against the internationally ongoing process of professionalization. The road toward professionalization in Flanders runs parallel to that in a lot of Western countries. The Flemish case is remarkable, though, in that issues of nomenclature and identity formation were already heavily debated, even taken to court, from the mid-1950s until the mid-1960s. While in North American and Australian educational programs and professional contexts, the gradual adoption of ...