The right to practice religion is recognised as one of the universal liberties transitional justice interventions are designed to defend, and religion is often mentioned as one of the cultural factors that impact on local transitional justice practices from below. Many human rights cases of abuse, however, are motivated by religious extremism and the association of religion with conflict has largely a discouraged reflection on its positive contribution to transitional justice. This field is undeveloped and the little work that elaborates its positive role is descriptive. This paper theorises the relationship between religion and transitional justice and develops a model for understanding its potential role that better allows an assessment of its strengths and weaknesses. The model is applied to original research conducted on ex-combatants in Northern Ireland, and concludes that only in very limited circumstances can religious actors make a telling contribution to transitional justice.Understanding what these circumstances are is the purpose of the model developed here.