The subject of the thesis research is the single market of the European Union. The aim of the research is to collect data on the EU single market on the basis of which a conclusion will be made on the impact of the COVID-19 pandemic, the impact of BREXIT on the EU single market and explore expectations for the future of the EU Digital Single Market through the EU4Digital Initiative Project. After the introduction, research methodologies and the mentioned data sources, the basic features of the European Union are defined. The process of accession to the European Union is explained, as well as a more detailed situation between the member states, candidate countries and potential candidate countries with the European Union. After elaborating the basic information about the European Union, the process of Croatia's accession to the European Union and the economic effects achieved by joining the Community are presented. Economic effects were observed on the basis of imports, exports, unemployment, gross domestic product and gross domestic product per capita. The "Four Freedoms" within the strategy of the European Union's single market are explained in detail, ie freedom of movement of goods, freedom of movement of capital, freedom of establishment and provision of services, freedom of movement of persons. In addition to the cooperation of the EU member states in the single market, the cooperation with the Eastern European countries, known as the Eastern Partnership, is also presented in more detail. The program for the single market of the European Union for the period 2021-2027 has been adopted. which possesses six fundamental goals in the said period. Brexit and Covid-19 are the biggest changes that have taken place in the European Union since 2020, and it was previously faced with changes in digital technology. The aim of this paper is to look at the overall situation in the European Union and to explore how digital technologies, the departure of the United Kingdom from the European Union and the COVID-19 pandemic will affect the single market of the European Union..