Various authors have challenged the traditional dichotomy of civic and ethnic nationalism. This paper presents the case study of Catalan nationalism in the Belle Époque. It argues for the usefulness of the lens of ‘Inter-Nationalism’ to highlight the fluctuating and labile character of nationalism and to move beyond the ascription of civic and ethnic types to certain regions by examining the exchanges between nationalist movements. It presents three areas in which Catalan nationalism in the Belle Époque moved between voluntarist-organic and inclusive-exclusive definitions and practices of nationalism: state organisation, gender and minority inclusion.