This chapter provides a comprehensive analysis of the legal treatment of ecocide in national legislation across various countries. It traces the historical emergence of ecocide as a criminal category, beginning with Vietnam and post-Soviet states, and highlights the influence of international legal debates, particularly those led by the International Law Commission. The chapter examines the evolution of legal frameworks in Latin America, notably Ecuador and Colombia, which introduced innovative approaches grounded in ecocentric and indigenous philosophies. It also explores legislative efforts in France, Chile, and Belgium, detailing their respective definitions, penalties, and conceptual challenges. Through comparative analysis, the chapter identifies common obstacles to the codification of ecocide, such as vague terminology, limited scope, and political resistance. It argues for the necessity of harmonising national laws with international standards to effectively address massive environmental destruction and promote accountability. The chapter concludes by emphasising the symbolic and practical importance of naming and defining ecocide as a distinct international crime.