In this article, we review the main impacts of the COVID-19 pandemic on the global energy sector and evaluate the implications of related policy responses on prospects for a transition to a climate-friendly energy system. In doing so, we differentiate between different types of countries and different dimensions of energy supply. Firstly, we assess the impacts on leaders and laggards in the transformation of the power sector, in terms of renewable power deployment and the phase-out of coal-fired power generation. Secondly, we consider impacts of the crisis on major exporters of oil and gas resources, focusing on a selection of G20 countries. We find that the impact of the COVID-19 crisis and related policy responses vary across different types of countries but also within large countries, such as the US and China. We conclude that the COVID-19 crisis deepens the gulf between leaders and laggards of the global energy transition and will exacerbate existing imbalances in an uneven energy transition landscape. This threatens the achievement of international climate targets and points to the need for concerted international action aimed at the phase-out of fossil energy resources.