It is proposed using certain indicators to assess the sustainable development of the EU countries and Ukraine: for the economic measuring - the global competitiveness index, the global innovation index and the index of economic freedom; for the social measuring - the social progress index, the human development index, quality of life index; for the environmental measuring - environmental performance index. The analysis of each selected indices of the EU countries and Ukraine is carried out. The methodology for calculating the ratio of the economic, social and environmental components of sustainable development for each EU country and Ukraine is presented. Attention is focused on the significant regional diversification of sustainable development and its components in the EU countries and Ukraine; the highest, middle and lowest levels of sustainable development of counties are identified. Impact: the methodology for the study of sustainable development, proposed by the authors on the example of the EU countries and Ukraine, is based on objective international ratings that have a transparent calculation methodology. These international ratings are constantly updated and cover most of the countries of the world. Therefore, the proposed methodology makes it possible to identify countries with the highest level of economic, social and environmental development; calculate the index of sustainable development of any country in the world.