The 60th anniversary of the publication of George Kelly's The Psychology of Personal Constructs was marked, in 2015, by the 21st International Congress on Personal Construct Psychology. His two volume work set out personal construct theory as a radical new approach to psychology. Although Kelly was a clinical psychologist, personal construct psychology has had an extraordinarily broad range of influence and application, extending beyond the clinical setting to include areas as diverse as education, organizational and management development, social psychology, the arts, law and politics. It presaged constructivist developments in many spheres of knowledge, and its innovative research methods have been used in a vast number of studies focussed on the exploration of personal and interpersonal meaning.The 21st International Congress was held in the UK at the University of Hertfordshire, forty years after the first such congress. This volume presents contributions by many of the Congress's delegates, whose chapters reflect the diversity of contemporary applications of personal construct psychology, and the continuing relevance and vitality of Kelly's ideas and methods.