According to the greenhouse gas (GHG) protocol for cities, GHGs are responsible for an estimated 75 per cent of global energy-related carbon dioxide emissions. This represents a key opportunity to tackle climate change. With the year 2023 and, in particular, the month of July delivering record-breaking temperatures, this demonstrates a clear need to accelerate decarbonisation and, in this context, to reduce the carbon footprint of cities. Further, acting on urban development addresses a number of key United Nations Sustainable Development Goals (UNSDGs). Many cities, however, are struggling to break away from a reliance on carbon and some are economically dependent on it. This paper seeks to investigate, through an energy justice lens, some first considerations of how to secure just and sustainable urban regeneration. It posits that energy justice, and its five core principles, is a useful analytical tool for considering the justice and development concerns related to the transition to a low-carbon world. The cities examined in brief in this comparative study are Bordeaux in France, Venice in Italy, Ho Chi Minh City in Vietnam and Bangkok in Thailand. The research posits that despite different trajectories, cities can play a leading role in ensuring justice and sustainability in our low-carbon world.