What relationship does international law have to transitional justice and what role has the United Nations (UN) played in shaping that relationship? The international legal history of this concept reveals that the UN has shifted from relying on international law to support nationally determined transitional justice efforts to expecting States to conform to a growing body of international legal standards it has set in this field. This turn to international legal hegemony and UN managerialism can marginalise some of the most pressing concerns of people attempting to overcome past large-scale abuses. In recent years, the UN has expanded its work in transitioning societies and scholars have recommended ways for better addressing the needs of their members. However, these measures seem partial at best, as they disrupt neither international law’s hegemony nor the UN’s managerial role in this field, which operate as major constraints on societies weighing their transitional justice options.