This paper reviews existing research on offender supervision in the Republic of Ireland and Northern Ireland. Three distinct areas are considered: practising offender supervision, experiencing supervision and decision-making in this sphere. The material presented draws on findings from a European-wide research action under the Cooperation in Science and Technology (COST) initiative. The review highlights some of the gaps in knowledge and the need to focus research attention in this area. This need is underlined by the expansion in probation’s role, both North and South. In common with other countries there has been a growth in referrals to probation and in the numbers of people subject to supervision, whether on a community sentence or under post-custodial licence conditions. This review highlights some of the relevant factors including the increased emphasis placed on public protection and attempts to reduce the prison population. The circulation of people through systems and the experiences, processes and decision-making involved are all areas that we argue are worthy of further research attention.