Countries with similar economies, cultures, languages and politics tend to have similar penal systems, albeit with some surprises and anomalies (Cavadino and Dignan, 2006). The purpose of this chapter is to explore the penal systems in the Republic of Ireland and Northern Ireland to see if they converge with other Western, developed, industrialised democracies and what lessons can be learnt from the anomalies that emerge. The chapter is divided into five sections. Imprisonment in pre-partition Ireland is reviewed before moving on to examine how the penal systems in the Republic and Northern Ireland developed after partition. Next, everyday prison life is explored to investigate how order and control is maintained as well as the extent to which prisoner needs and quality of life issues are addressed. Lastly, the suitability of the accountability mechanisms employed are reviewed to determine their ability to promote change and encourage ongoing improvements and reform in Irish and Northern Ireland prisons.