Background: Out-of-hospital cardiac arrest (OHCA) remains a major public health challenge across Europe. While prehospital emergency medical services (EMS) vary widely, the degree to which regional infrastructure, dispatch guidance, and community responder frameworks influence clinical outcomes when mapped against standardized reporting templates remains insufficiently synthe-sized. This scoping review evaluates European OHCA evidence across standardized Utstein re-porting domains to analyze prehospital system factors, responder interventions, and clinical out-comes. Methods: Following PRISMA-ScR guidelines and Joanna Briggs Institute (JBI) methodology, a systematic literature search was performed across PubMed, Scopus, and Web of Science (January 2021–March 2026). From 8,882 records identified, 2,126 full-text articles were evaluated using a Population, Exposure, Outcome (PEO) framework. Data were synthesized across four core Utstein domains. Results: Forty three primary studies (N = 43) were included. System Factors demonstrated that prolonged ambulance response intervals severely diminish survival, particularly in sparsely populated rural sectors. Dispatch Protocols highlighted that rapid dispatcher recognition signifi-cantly increases telephone CPR instructions and community resource activation. Under bystander a prominent gap was identified between public AED availability and actual lay bystander deployment (< 5%). Dispatched Volunteer Community Responders (VCR) and First Responders (FR) achieved median arrival time-gains of 4–5 minutes; however, survival benefits were descriptively observed primarily when early arrival facilitated ultra-early defibrillation or high-quality CPR. Clinical Out-comes confirmed that 30-day survival and favorable neurological recovery (CPC 1–2) remain highly variable, heavily constrained by reporting heterogeneity. Conclusions: Strengthening early links in the chain of survival—specifically dispatcher recognition, app-alerted volunteer dispatch, and public defibrillation—is consistently associated with improved clinical survival. Universal adoption of the updated Utstein 2024 reporting template is essential to eliminate reporting heterogeneity and enable meaningful cross-system benchmarks across Europe.