The aim of this paper is to examine the sustainability of Japan’s and South Korea’s energy policies. For the analysis, categories framed by Holgar Rogall for identifying a sustainable energy policy were used. Using official data from the UN and government authorities of both countries as well as secondary literature, a comparison of international goals and legal norms and an analysis of developments in energy policy since 1990 were conducted. Their results show that Japan and South Korea pursue quite different energy policies. In more than half of the criteria, Japan can be seen as having a sustainable energy policy. The country still has to improve its use of energy sources, as it is too dependent on fossil fuels and thus needs to accelerate the development of renewable energies. South Korea’s energy policy, however, cannot yet be classified as sustainable. The government still rejects international commitments regarding climate change, a conclusion that is reflected in development since 1990: greenhouse gases rising at a high speed, coupled with low energy efficiency and dependence on fossil fuels. Despite sharing the same basic conditions, the energy policies of Japan and South Korea differ fundamentally.