Croatian nationalism is the set of political, economic, civic, cultural, and ethnic ideologies that promotes the interests and influences within Croatia, the Croat people, Croatian citizens and the Croatian diaspora. It indicates the aspects that characterize and distinguish Croatian society as an autonomous community. The national identity and self-determination of Croatia has seen significant dynamism throughout its history. The cultural and ethnic unity of Croats has been a key component of nationalism since the 19th century. Roman Catholicism and the Illyrian movement influenced early-stage nationalist ideas. The claim and promise of historic statehood for Croats has informed many varieties of modern Croatian nationalism. This created the concept of Greater Croatia, the belief in the equivalence between the territorial scope of the Croatian people and that of the Croatian state. This regional sphere of influence spreads Croatian nationalism across Southeast Europe.
Following the independence of Croatia in 1991, modern Croatian society has been dominated by ethnic nationalism and historical revisionism. Its deepening integration within Europe and the broader Western world, has led to increased legal and rational concepts of nationalism such as the shared Croatian language, cultural traditions, national values, and citizenship. Croatian nationalism exists across the ideological spectrum – from the left-wing to the right-wing – of the country's political establishment. Croatia has strong ultranationalist (or hyper-nationalist) currents that advocate for extreme interpretations of Croatian hegemony, which has at times led to ethnic tension and political violence. Many national symbols and cultural exports define Croatian nationalism, including its national flag, anthem, soccer team, tourism sector, and cuisine, among others.