Ron Lippitt, an innovator throughout his distinguished career, was one of the founders of group dynamics and the “T-group” (sensitivity group), a cofounder of the National Training Center for Group Dynamics at the Massachusetts Institute of Technology, and again later was a cofounder of the Center on the Research for the Utilization of Scientific Knowledge at the University of Michigan. A pioneer in the development of experimental social psychology, he is renowned for his classic work on the effects of democratic, autocratic and laissez faire leadership of small groups, and for his later work on planned change. Throughout his life, he demonstrated the power of controlled research in natural settings, creating scientific foundations for small group, organizational and societal change. His hundreds of writings span articles, chapters, and books that contribute his insights and methods to resolve organizational and social problems. He leaves behind a rich legacy for researchers, consultants, organizational and societal leaders, and students.