This paper explores the role of apology in the resolution of conflict through mediation. The paper outlines the distinctive features of mediation that contribute to its unique potential to help restore relationships, with apology forming a potentially transformative aspect to this. However, not all apologies are the same and not all apologies are effective. Working from the literature, this article seeks to clarify the characteristics of apology that are likely to make it effective in mediation. A review of the literature also reveals a range of moderating factors that can further impact the effectiveness of apology. Particular attention will be paid to these moderators in considering what contributes to a template of apology effectiveness in the context of mediation. In this study, the first of its kind in an Irish context, empirical data from an online survey of 97 practicing mediators along with in-depth interviews with a sample of 24 organisational mediators is analysed, in relation to five core questions aimed at determining the fundamental nature of apology in mediation. While the mediators who were interviewed operate in the ‘organisational’ context, the mediators we surveyed practice across a range of mediation contexts, including civil, workplace, and family. Therefore the context, in this case, was not controlled. Nonetheless, the analysis yields insights that support the view found in the literature that an apology can, in certain circumstances, be an effective means of transforming the mediation process. A summary of these findings indicates that: (a) Practicing mediators confirm that apology is a prominent feature of mediation, and that the process represents fertile soil for apology. This represents a challenge to the mediator where apology is not forthcoming. (b) Where an apology is forthcoming but hesitant, skilled mediators can act as a conduit of apology between parties. (c) The data also suggests that a high-quality apology, issued spontaneously, can have a transformative effect on the dispute, particularly where the relationship is on-going. The main contribution of this paper lies in its potential to inform mediation practice, by illustrating the potential impact of apology and by offering role guidance to practitioners who wish to facilitate such potential where circumstances allow. The paper also contributes to the literature through insights offered by the research respondents which shed new light on existing themes. Ultimately this research argues that mediation can accommodate apology as a potent means of repairing relationships, and that the mediator can play a key role in this. The paper will make the case for a nuanced, yet structured approach to apology, one that needs to be reflected in mediator training and practice. The case for further research is presented at the end.