This thesis deals with the topic of homegrown Islamist terrorism in the European Union. The target of this research is to provide an interpretation of the homegrown terrorism in the political discourse of the EU as an entity and selected member states - France, the United Kingdom and Slovakia. Building on assumptions of social constructivism and securitisation theory, the thesis explores the patterns in the discourses during the years 2015 - 2018 and seeks to identify potential similarities and differences in the political discourses of respective countries. While studying the changes in the discourse, the thesis analyses how the issue of homegrown terrorism has been securitised, thus how the narratives of political authorities shape perception of the homegrown terrorism as a major threat for Europe. In order to organise the arguments in a more objective manner, the research uses a qualitative method of thematic analysis. Our findings suggest that themes which are of general concern in all the discourses are, among others, prevention of terrorism and radicalisation, the significant role of the internet in spreading Islamist propaganda and the problem of returning foreign fighters However, some themes were identified as state-specific, such as highlighting the homegrown nature of current terrorism...