An overarching, supraordinate identity (e.g., European identity) can enhance intergroup relations if individuals recategorize ingroup and outgroup members into one, unified group. Yet, in conflict‐affected societies, ethno‐national identities may promote negative intergroup attitudes and behaviours. The effects of European and ethno‐national identities in combination have yet to be explored in childhood. If they can be integrated, the inclusivity of a supraordinate European identity may be felt despite the divisiveness of ethno‐national identities in post‐accord societies. This research assesses supraordinate identity integration in relation to quality intergroup contact and cross‐group friendships among the post‐accord generation in Croatia, Kosovo and Republic of North Macedonia (RNM). These sites have relatively recent conflicts, but varying relationships to the EU. Data were collected from 382 children aged 7–11, split evenly by minority and majority status (Croatia n = 90; Kosovo n = 107; RNM n = 185). Children across all three sites had integrated ethno‐national/European identities. Levels of identity integration varied by site, but not group status. Identity integration was positively and significantly associated with quality of outgroup contact and number of cross‐group friends, and this relationship varied by site. Integrated supraordinate identities have promising implications for intergroup relations and the future of peacebuilding in Europe. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement.