Understanding and promoting agency are crucial to addressing urgent social problems of our time. Through agency, we can take transformative steps toward the future that ought to be. This book shows how contemporary conceptualizations from cultural-historical activity theory can inform research and practice that fosters positive change. At the core of this book's novel approach to agency and transformation are three motifs: motives, mediation, and motion. These take inspiration from the original work of Vygotsky and subsequent generations of scholarship, enabling us to understand agency in ways that recognize the social and cultural aspects of agency without losing sight of individuals' contributions to changing their own lives and the lives of others. Referring to connections between learning, pedagogy, and agency, the chapters address power, freedom, and the future in contexts including adolescence, school exclusion, children's activism, Indigenous communities, environmental activism, homelessness, childbirth, and young people during the COVID-19 pandemic.