This chapter deals with the concept of constitutional identity as it is understood in the Czech Republic. First, it defines the content of the ‘legal’ constitutional identity developed by the Czech Constitutional Court and the process of its formation in court case law. Subsequently, the chapter explores the normative effects of the judicially created Czech constitutional identity, especially in relation to the European Union (EU) and the principle of the primacy of EU law. Finally, it problematises the concept of Czech constitutional identity, introducing the ‘popular’ strand, which goes beyond the constitutional text and is built around formative historical events in Czech(oslovak) history. The authors argue that it is here where the gap between the ‘legal’ constitutional identity and the ‘popular’ constitutional identity is growing, with significant repercussions for the Czech constitutional order as well as for its relationship with EU law.