The third edition of the Handbook of Thanatology is an accessible volume that offers essential knowledge in the field of thanatology in a format that is practical for both novices and those with extensive experience in the field. Using ADEC's Body of Knowledge Outline, the editors guided authors for this third edition of the Handbook to elaborate on the content baskets suggested by the Outline's headings. Like the Outline, this edition of the Handbook is comprehensive but not exhaustive. Initial chapters emphasize foundational topics including definitions of death, death-related attitudes, the epidemiology and demography of death, end-of-life care, and memorialization. The middle chapters focus on grief theories, distinct conceptualizations and considerations of grief based on cause of death, and problematic grief. The volume concludes with chapters highlighting the broad topics of death education, professional practice, history of the field, social presentations of death, and non-death losses.