The transition towards low-carbon societies is creating winners and losers, raising new questions of justice. Around the world, litigation increasingly articulates these justice questions, challenging laws, projects and policies that aim to deliver climate change adaptation and/or mitigation. In this Perspective, we define and conceptualize the phenomenon of ‘just transition litigation’. This concept provides a new frame for identifying and understanding the diverse justice claims of those affected by climate action. We set out a research agenda to further investigate this phenomenon, with a view to enhancing societal acceptance and support for the transition.