The assessment of sustainability requires that the diverse values of the stakeholders are represented in the context-specific interpretation of sustainability and in the choice of a desired course of action. Sustainability is a broad concept, and the stakeholders in sustainability are many. In order to have effective stakeholder engagement, it is crucial that all the relevant stakeholders are identified early in the process. In urban development projects, some stakeholders may be obvious, but there might be others who are excluded from the usual decision-making processes and may bear disproportionate environmental, social or economic costs leading to inequitable outcomes. This situation has created the need for a systematic approach to defining and identifying stakeholders for different contexts. This paper evaluates existing approaches for defining and identifying stakeholders in development projects and the requirements of a sustainability assessment process. From this analysis, an approach for defining and identifying stakeholders appropriate for sustainability assessment has been developed. The paper also argues that it is important to map out the levels of interest of different stakeholders in relation to the power that they hold. This is useful in determining the appropriate engagement techniques at each stage of a project and also in understanding any potential conflicts. It is thus important to understand the relationships between the different stakeholders because this can affect the success of the engagement process. Such a mapping of stakeholders can also be useful in anticipating their expectations.