On January 31, the United Kingdom’s long and tumultuous departure from the European Union concluded with Brexit Day. This monumental, and by some, staunchly condemned, process ushered in a breadth of legal impacts, especially in regards to national environmental law and policy. EU directives previously served as the foundation for a large contingency of environmental standards, environmental protection regimes, conservation schemes, and enforcement and compliance in the U.K. Additional implications of Brexit include those at the intersection of agriculture and the environment, business and trade implications, sustainability efforts, chemical regulation, renewable energy development, the Paris Accord and other climate goals, and a variety of multinational treaties and directives. In short, the impacts on environmental governance were, and are, enormous and far-reaching.