Water management is principally used here to review current knowledge in relation to social justice in the allocation of natural resources and environmental management. The sphere of human needs provided by water is described, and a water benefits approach to measuring the overall well-being from water allocation decisions is introduced. The basic concepts of social justice—procedural, interactive and distributive justice, equity, fairness, and lay environmental ethics—are outlined, along with their limitations when applied in different cultures. The premise of scale and justice judgments is posed with the example presented in watershed development in Andhra Pradesh, India. The requirement for research into ways that justice can be incorporated within the dynamic systems approaches that are becoming prevalent in ecosystems management is proposed, with the example of a fisheries-based management cycle provided to demonstrate how this can occur. The importance of incorporating and integrating time, spatial, and social dimensions into framing justice research is demonstrated. Suggestions for future research are made throughout.