This chapter outlines the expanding and essential role of psychologists in the fire service, highlighting a critical divergence from police-centered models of public safety psychology. Firefighters face distinct psychological challenges rooted in occupational culture, trauma exposure, and team dynamics that require a specialized approach. The chapter examines historical developments, contrasts police and fire psychological integration, and calls for the emergence of fire service psychology as a distinct subdiscipline. Four core domains (assessment, intervention, consultation, and operations) are examined through the lenses of law, clinical practice, and organizational management. Models such as embedded clinicians, contracted services, and regional care collaborations are presented alongside critiques of traditional Employee Assistance Programs (EAPs) and discussions on the Frye and Daubert standards. Emphasizing cultural competence, interdisciplinary practice, and systemic reform, the chapter argues that psychologists must serve not only as clinicians but also as strategic partners embedded in the fire service infrastructure. The future of fire service psychology depends on purpose-built tools, targeted training, and sustained partnerships between departments and clinicians.