Environmental assessments increasingly call for just transformations, yet do not offer concrete visions of what these might be. This paper conceptualizes and operationalizes Earth system justice (ESJ) through articulating just ends which minimize significant harm to humans from Earth system change while ensuring access to needed resources for all and just means which involve reallocation of resources, responsibilities, and risks. We argue that Earth system justice is underpinned by recognition and epistemic justice, inclusivity and procedural justice, and corrective and distributive justice with a scope that encompasses intragenerational, intergenerational, and interspecies justice concerns. This Earth system justice framework provides the theoretical underpinning for assessing proposals for international environmental policy based on Earth System Boundaries (ESBs) and for proposing just approaches to sustainability transformations.