How does the COVID-19 pandemic affect States’ obligations under international law? This is a question of not just academic interest but real importance for people’s lives. After all, whether States abide by international law—and whether international law is fit for purpose—is vitally important for everyone from refugees exposed to the virus in unsanitary detention centers to national leaders fighting disinformation campaigns and safeguarding vaccine supply chains. International law has been central to the world’s response to the pandemic from the start—even if the participants did not always realize it. International law, after all, required States to take certain actions to detect and prevent the spread of the novel coronavirus. Some governments responded quickly and effectively, significantly reducing the impact on their populations, but many others were far less successful. Many have made matters worse by responding to the virus in ways that exacerbated the toll on the most vulnerable populations, violating their international law obligations in the process. Moreover, some States have used the pandemic as an excuse for delaying elections or for denying arrested persons adequate legal representation. This Article examines the many ways in which COVID-19 is straining the rules and norms of international law. It considers the five main bodies of international law implicated by the pandemic: international humanitarian law, international human rights law, immigration and refugee law, international cyber law, and the rules and regulations of the World Health Organization. It outlines the obligations each body of law impose on States, and how those obligations apply during the current pandemic. It concludes with several proposals for reform to the international legal system so that the world can prepare to more effectively address the next inevitable pandemic.