European identity among youth remains under-studied despite having the potential to promote inclusive benefits. Through a rapid evidence assessment (REA), this paper addresses two aims. First, it synthesises definitions of European identity among children, adolescents and young adults through thematic analysis, and summarises measurements. Second, it summarises the constructs associated with European identity among youth, providing a broad overview of existing research. Based on thematic analysis, European identity is operationally defined as a complex identity with which youth may choose to identify, uniting people based on a diverse range of factors but acknowledging the diversity of national roots and, in turn, affording benefits due to the sense of belonging it provides. School-based interventions and curricula, knowledge about Europe and the EU, political trust, benefits of the EU, and cross-border experiences, along with enhanced intergroup attitudes and civic engagement, are associated with stronger European identification. Avenues for future research are identified, including the need for a developmentally appropriate measure of European identity, the investigation of its relationship with other constructs, and exploring the potential of curricular interventions to promote the inclusive aspects of European identity on a national scale, particularly among younger pupils.