Abstract: Despite the lack of systemic examination of the extent and manifestations of informal housing in Canadian cities, there is consistent evidence that it does occur and is tolerated by governments. This paper examines the persistence of illegal housing in Calgary to provide insights into processes that give rise to and motivate state toleration of illegal housing. It also explores the complex interactions between state agents, illegal housing operators, tenants, and communities to comment on how illegality is contested, reinforced, and even ignored by the various actors involved.