["Nations and Nationalism, EarlyView. ", "\nABSTRACT\nThis article explores the relationship between insularity and territorial demands, focusing on whether island territories are more likely to support regionalist and secessionist parties. To address this question, we compare electoral support for such parties across island and mainland territories using a large‐N dataset. Our findings indicate that island regions consistently display higher levels of support for regionalist and secessionist platforms, and a more salient regional identity compared to their counterparts in continental territories. Additionally, we consider different explanations grounded in the literature on nationalism to better understand this pattern. By examining how insularity interacts with territorial demands, this study offers new insights into the political relevance of islandness and contributes to the broader literature on territorial politics and nationalism.\n"]