This paper argues that transitional justice needs to adopt a participatory approach to achieve longer-term sustainability, shifting away from the top-down ‘one-size-fits-all’ approach to allow ‘voices from below’ to be heard and heeded. It critiques dominant interpretations of key transitional justice concepts, and links them to the difficulties of post-conflict transitional justice in a range of violently divided societies. Popular participation and local agency, it is argued, is necessary to achieve ends identified in much transitional justice discourse, and to embed mechanisms for the creation of sustainable peace. A Northern Ireland initiative (the Ardoyne Commemoration Project) will be explored in-depth, illustrating how a bottom-up ‘truth-telling’ process can make a significant contribution to transitional justice and casting doubt on the validity of the deference to legal dominance in current policy and practice. The paper recommends that knowledge available in development studies and participatory theory be applied more clearly in debates and approaches in transitional justice.