This Handbook examines the interplay between metamemory and memory. Each contributor discusses cutting-edge theory and research that, in some way, showcases the symbiotic relationship between metamemory and memory. Together, these chapters support a central thesis, which is that a complete understanding of either metamemory or memory is not possible without understanding their mutual influence. The inspiration for this volume was the life and research of Thomas O. Nelson, whose pioneering and influential research in the fields of metamemory and memory consistently highlighted their integrated nature.