Background/Objectives: Out-of-hospital cardiac arrest (OHCA) has persistently low survival rates. While advanced airway management (AAM) is crucial during cardiopulmonary resuscitation, optimal timing remains unclear. This study examined the association between early AAM and clinical outcomes in adult OHCA patients. Methods: This retrospective study analyzed Korean nationwide OHCA registry data (August 2019–December 2022). Adult patients with emergency medical service-treated OHCA of presumed medical origin receiving AAM were included. Early AAM was defined as airway placement within 5 min of CPR initiation. Time-dependent propensity score matching controlled for selection bias and time-related confounding. Structural equation modeling examined associations between AAM timing and other prehospital interventions. Primary outcome was survival to hospital discharge with good neurological recovery (cerebral performance category 1–2). Results: Among 51,869 patients receiving AAM, 27,591 received early AAM and 24,278 received delayed AAM. After propensity score matching, 12,014 patients were included per group with balanced characteristics. Early AAM was associated with higher prehospital return of spontaneous circulation (11.8% vs. 10.5%; adjusted RR 1.21, 95% CI 1.12–1.29) and favorable neurological recovery (5.8% vs. 5.1%; adjusted RR 1.12, 95% CI 1.01–1.23). AAM timing correlated with timing of other critical interventions, including rhythm analysis and epinephrine administration. Conclusions: Early AAM within 5 min of CPR initiation was associated with improved neurological outcomes and increased prehospital ROSC in OHCA. Airway timing may indicate overall resuscitation quality, emphasizing the importance of coordinated, timely prehospital interventions.