Economic and energy security has always played a big role in the well-being of the state, which is especially important in times of war. Developing mechanisms to counter internal and external threats, such as war, is a fundamental aspect of ensuring national security. The purpose of the study is to analyze the scale of threats in the economic and energy sectors of Ukraine and to explore the possibilities and ways of ensuring their stability in the conditions of war and in the post-war period. During the period of the full-scale invasion, the Russian Federation has already destroyed 30-40% of the sources of renewable energy in the southern and southeastern regions of Ukraine. On February 2023, Ukraine temporarily lost 44% of its nuclear generation, 75% of its thermal power plants capacity, and 33% of block cogeneration plants. Since the beginning of the war, 7,704 million Ukrainians have left abroad, millions of citizens have moved to Western Ukraine. The number of the working population is significantly reduced, due to which the purchasing power of the population has decreased by 12-15%, and at the same time the value of GDP has decreased and inflation has increased. Ensuring the independence of the national economy and energy industry, their stability and sustainability are one of the main functions of the state. Ukraine actively uses tools to ensure economic and energy security: maintaining unchanged tariffs for housing and communal services, partial tax reduction, fixing the exchange rate of the hryvnia and introducing currency restrictions, using renewable energy sources, etc. Public initiatives are also being formed to ensure security in the economic and energy sectors, which is an important factor for a successful outcome, because only the cooperation of the state, business and society as a whole will lead Ukraine to qualitative changes, including ensuring economic and energy security. PEST analysis demonstrates the existence of justified political, economic, social and technological prerequisites for the successful recovery of the national economy, taking into account the issues of economic and energy security. Specific, actionable recommendations on how to tackle economic security challenges directly during the war and in the post-war period were provided, including digitalization of public services, use of decarbonization strategies, and human capital development.