Summary: The establishment of the European Pillar of Social Rights is an expression of the European Union’s (EU) concern for social security, which is a fundamental aspect of citizens’ lives. This article aims to analyse and describe the issue of social security protection of EU citizens in the context of the European Pillar of Social Rights. The article shows the EU’s attitude towards social security, describes the principles and assumptions resulting from the European Pillar of Social Rights, and their implications for the social security of citizens of EU member states, with particular emphasis on Poland. The article also explains the impact of the positive aspects of the European Pillar of Social Rights on national security.