Platoon leaders in the fire services are responsible not only for firefighting and rescue operations but also for a wide range of administrative and managerial duties (for example, personnel supervision). However, existing competency models and guidelines for fire service leaders often fail to account for the dual role these leaders play—balancing frontline operational demands with organizational and personnel-related responsibilities. To identify the necessary knowledge, skills, abilities, and other characteristics (KSAOs) we first conducted 25 in-depth, semistructured interviews with active platoon leaders applying the critical incident technique. The analysis of behavioral anchors derived from the interviews resulted in 38 highly-specific competences. We collapsed this initial list of competences into a more streamlined model of 21 competences to increase its applicability for fire services. Survey data from a follow-up study with N = 601 firefighter leaders confirmed the importance of the final model’s competences. In addition, to account for a continuously changing firefighting environment, we asked participants to rate the future importance of competences in a five-year scope and identify potential future challenges for platoon leaders within the same time frame. Our research provides valuable insights into the wide-ranging requirements of dual-role leaders in high-reliability contexts by addressing both operational and managerial competences. Implications for fire services, their official guidelines, and the potential benefits of incorporating the competency model into selection and development processes are discussed.