The paper presents the process of integration of Međimurje Croats into the modern Croatian nation from the middle of the 19th century until the integration of Međimurje into the Kingdom of Serbs, Croats and Slovenes, which has not been dealt with in historiography until now. Without a developed citizenry and intelligentsia, as well as vital cultural and political institutions, it was impossible for the majority of the peasant population to participate in the political and cultural life of Međimurje and the definition of national identity. Međimurje also encountered important issues of the integration process, such as the issue of the equality of peoples, languages or the totality of Croatian countries. In researching the process of Croatian national integration in Međimurje, the question of when it begins, when it ends, and through which developmental stages the process went, and who were the individuals involved in the integration process and how they acted, is particularly important. Accordingly, the work is based on the model of historian Miroslav Hroch, who builds his model on the example of several medieval nations, the so-called of small nations that at the beginning of this process did not have their own state or complete social structure. For the Croatian people in Međimurje, the events at the turn of the 19th and 20th centuries that preceded the accession of Međimurje to the Kingdom of Serbs, Croats and Slovenes at the Trianon Peace Conference in 1920 are important. The beginning of the 20th century brings changes that create a new civil society and thus modern forms of cultural integration processes in Međimurje. The Croatian intelligentsia mainly consisted of young priests such as Luka Purić, Vinko Žganac and Juraj Lajtman, but also the lawyer Ivan Novak, who encouraged Croatian state-legal and political thought as well as cultural, administrative and Croatian national integration in Međimurje with the aim of preventing the Hungarian elite from trying to make Međimurje and integrating the Croats of Međimurje into the Hungarian nation. Hungarianization was largely resisted by the Catholic Church and part of the Catholic clergy, who guarded and defended the Croatian national idea and assumed the role of spreading Croatian national consciousness in the political, economic and linguistic fields. The paper tries, among other things, to highlight the peculiarities of the policy of Hungarianization and denationalization of the Croatian people in Međimurje, to highlight the peculiarities of the development of primary schooling and education in Međimurje, to point out the importance of Međimurje belonging to the Zagreb Archdiocese, as well as the role of oral folk songs, culture and music of the Croatian people in Međimurje. The collapse of the Austro-Hungarian Monarchy created the possibility of completing the national integration process in Međimurje by including it into the SHS Kingdom.