Social impact assessment is a field of applied social research that is now over 50 years old. With its ongoing evolution in practice and thinking, social impact assessment is a valued part of project development and will continue to be so. Over time, there has been a shift in understanding, from social impact assessment being a regulatory tool to now being the process of managing social issues throughout the life of a project. The range of issues considered has become much wider, now also including human rights. More than a tool or approach, social impact assessment is a discourse, a body of scholars and practitioners, a paradigm, and a philosophy about development and the rights of affected communities. The proper consideration of social impacts is now expected by all project stakeholders and is a requirement of international standards and project financing. There is now recognition of the need for projects to gain and maintain social acceptance, or a social license to operate and grow. Key current issues include: human rights; doing good rather than just doing no harm; benefit-sharing arrangements; Indigenous-led social impact assessment and community-based social impact assessment; and gender, LGBTQI+, two-spirit people, and intersectionality. Social impact assessment is increasingly being used to assist communities in negotiating Impact and Benefit Agreements (or Community Development Agreements).