This article offers a critical literature review on the debate on constitutional identity, combining a synthesis of existing literature with a critical reframing of the concept’s theoretical and methodological foundations. While constitutional identity has become increasingly prominent in legal and political debates – particularly within the European Union – its meanings and functions remain contested. The article develops a typology of approaches to constitutional identity, distinguishing two main strands. First, it examines constitutional identity as a legal doctrinal notion. In this sense, identity can function either as a static concept – anchored in an unchanging normative core that limits political or legal interference – or as a dynamic concept, shaped through interactions between domestic constitutional orders and external legal ideas and practices. Second, the article turns to the descriptive use of constitutional identity, understood as a way to explain how a political community understands itself through its constitution. This part surveys key philosophical debates, including how constitutional identity negotiates sameness and difference, how it evolves over time, how it relates to competing conceptions of the constitutional subject, and how it is constructed through narrative, symbolism, and social practice. The article concludes by arguing that if constitutional identity is not a fixed essence but a dialogical and constructed assemblage of identities, then its study must go beyond the legal domain. It calls for a deepening of the interdisciplinary research agenda that includes insights from philosophy, sociology, discourse theory, and literary studies.