The phrase “private prison” has become a term of opprobrium, and for good reason. There are numerous cases of mistreatment and mismanagement at such institutions. However, in the context of immigration detention, this caricature hides a complex phenomenon that is driven by a number of different factors and involves a diverse array of actors who provide a range of services. This working paper employs research undertaken by the Global Detention Project (GDP)—an inter-disciplinary research project based at the Graduate Institute of International and Development Studies—to help situate the phenomenon of the privatization of immigration detention within a global perspective. Part of the difficulty in assessing this phenomenon is that our understanding of it is based largely on experiences in English-speaking countries. This working paper endeavors to extend analysis of this phenomenon by demonstrating the broad geographical spread of privatized detention practices across the globe, assessing the differing considerations that arise when states decide to privatize, and comparing the experiences of a sample of lesser known cases.