The Royal Commission into Institutional Responses to Child Sexual Abuse is the largest royal commission in Australia's history and one of the largest public inquiries into institutional child abuse internationally. With an investment from the Australian government of half a billion dollars, it examined how institutions with a responsibility for children, both historically and in the present, have responded to allegations of child sexual abuse. Announced in the wake of previous Australian and international inquiries, public scandals and lobbying by survivor groups, its establishment reflected increasing recognition of the often lifelong and intergenerational damage caused by childhood sexual abuse and a strong political commitment to improving child safety and wellbeing in Australia. This article outlines the background, key features and innovations of this landmark public inquiry, focusing in particular on its extensive research program. It considers its international significance and also serves as an introduction to this special edition on the Australian Royal Commission, exploring its implications for better understanding institutional child sexual abuse and its impacts, and for making institutions safer places for children in the future.