This is an overview of the broadly-defined field of school supervision, which encompasses the activities of individuals with a range of titles including principal, department head, team coordinator, superintendent, curriculum director, instructional supervisor, and others. Spanning nearly 40 years, the handbook serves to unify two generations of research by bringing the major works in the field together in an inclusive collection. The 52 chapters, authored by 77 recognized scholars, are organized into nine sections examining supervision as a field of inquiry and as a profession; recognizing the internal and external forces of change in the field; presenting key theoretical concepts, and practical guides; and pointing to future directions.