This special issue of the International Journal of Group Tensions examines the contribution of psychology to societal transformation worldwide and the impact of societal transformation on psychology. In this introduction, I review the aims and scope of the journal and the focus of the special issue. Second, I identify several key consequences of societal transformation that are not bounded by culture, nationality, or politics, underscoring the psychosocial outcomes. Third, I articulate the role of psychology in societal transformation, highlighting the conceptual, methodological, and practical tools available to describe, study, and effect change. I also address psychosocial explanations of resistance to societal transformation. Fourth, I discuss the impact of societal transformation on psychology as a discipline and profession, noting how such transformation has influenced academic training and professional practice in psychology. I also note how societal transformation has altered public opinion about psychology. I conclude by providing an overview of the articles that comprise the special issue, underscoring their shared themes.