The paper defines the content of a thin and a thick versions of the 'legal' constitutional identity developed by the Czech Constitutional Court as well as a ‘popular’ conceptualization of identity, which goes beyond the constitutional text and is built around formative historical events in Czech(oslovak) history. It explores the normative effects of the 'legal' identity, especially in relation to the EU. It argues that an open conflict between the Czech constitutional identity with the EU law is unlikely in the near future. Finally, the article shows that the gap between the ‘legal’ constitutional identity and the ‘popular’ constitutional identity is growing, which has significant repercussions for the Czech constitutional order. There are two ways how to address this situation – to forge a strong sense of constitutional patriotism among the people, and to enhance participatory mechanisms through which the people can participate in developing the Czech constitutional identity.