The level of renewable energy use and economic development of a country, as separate indicators, have an influence on the level of energy resource imports, but the mutual impact of renewable energy sources and gross national product on the growth or decrease of energy imports dependency have not been studied. Therefore, the aim of this study was to evaluate the energy security of European countries by taking into account the consumption of renewable energy sources and the economic development of the countries. In particular, the article examines the relationship between energy import dependency, gross domestic product (per capita), and renewable energy sources in 27 countries in the European Union. Regression analysis of data on EU countries for 11 years (from 2011 to 2021) was used to determine the non-linear influence of gross domestic product and renewable energy use on energy import dependency. This influence was simulated by a second-order regression equation. The analysis of the equation for extremes made it possible to conclude that with a share of energy from renewable sources at the level of 32%, the economic development of a country does not require an increase in energy import dependency, and with larger values of energy from renewable sources, a decrease in energy import dependency may occur. In addition, according to the analysis of the obtained mathematical dependence, it is recommended that countries with a gross domestic product of up to 10,000 euros per capita use renewable energy sources at the level of 40%. For the countries with a domestic product of up to 30,000 euros per capita should use renewable sources at the level of 50%. For countries with a gross domestic product of more than 30,000 euros per capita, renewable energy sources at a level of more than 55% is recommended. A high level of renewable energy use will allow a country to increase its gross domestic product without a significant increase in energy import dependency, and at the level of renewable energy sources of more than 32%, an increase in gross domestic product does not actually lead to an increase in energy import dependency. An increase in the use of renewable energy sources above 40% of the total consumption of energy resources in a specific country, in particular, and in the European Union, in general, will ensure an increase in energy security and an increase in the level of energy independence.