Reconciliation is an aspect of conflict resolution, with similar behavioural patterns documented in non-human primates, human children, and human adults of non-Western, non-industrialized cultures. Reconciliation amongst adults of industrialized societies has rarely been studied. We observed naturally occurring conflicts between adults, captured by public security cameras in England. Reconciliation was found in one-quarter of all conflicts and was more prevalent in milder conflicts. Reconciliation typically occurred spontaneously between opponents — and was found within friendship groups and across stranger groups. Reconciliation between opponents also appeared to be stimulated by peers, law enforcement, or shared objects. In some instances, reconciliation extended beyond the initial conflict dyad toward victimized third-party peacemakers. These findings add to growing cross-cultural and cross-species evidence demonstrating the presence and function of post-conflict reconciliation. We extend the repertoire of reconciliatory behaviour and introduce five common features of reconciliation that are central to the study of adult peacemaking.