ABSTRACT: There is increasing convergence between criminal and immigration law as states respond to the challenges of international migration by erecting and enforcing tougher visa and border controls. Many countries have put the criminal justice system to work in managing migration. The numbers of foreign nationals in prison or in immigration detention centres have consequently surged. This paper examines the particular perspective that criminology provides in explaining and critiquing these developments. While the field has been slow to respond to immigration detention, often clinging to a nationalist vision of the administration of justice, over the past decade scholars in the nascent field of “Border Criminologies” have begun assessing the changing architecture of crime and punishment. Their research has drawn on the traditions of applied research about state control, producing accounts of policing, imprisonment, and detention. While work still needs to be done to broaden the intellectual reach of this new subfield, this paper argues that criminology offers a rich, critical heritage as well as a set of methods through which to understand these policy developments.