School social workers are integral to the school mental health workforce and the leading social service providers in educational settings. In recent decades, school social work practice has been largely influenced by the multi-tiered systems of support (MTSS) approach, ecological systems views, and the promotion of evidence-based practice. However, none of the existing school social work reviews have examined the latest characteristics and outcomes of school social work services. This scoping review analyzed and synthesized the focuses and functions of school social workers and the state-of-the-art social and mental/behavioral health services they provide. Findings showed that in the past two decades, school social workers in different parts of the world shared a common understanding of practice models and interests. Most school social work interventions and services targeted high-needs students to improve their social, mental/behavioral health, and academic outcomes, followed by primary and secondary prevention activities to promote school climate, school culture, teacher, student, and parent interactions, and parents' wellbeing. The synthesis also supports the multiple roles of school social workers and their collaborative, cross-systems approach to serving students, families, and staff in education settings. Implications and directions for future school social work research are discussed.