Nurse-led care has emerged as a critical model of service delivery in psychiatric and mental health settings, particularly in response to increasing global mental health burden, workforce shortages, and the need for cost-effective, patient-centered care. This systematic review synthesizes evidence from the last ten years to evaluate the effectiveness of nurse-led interventions for psychiatric patients across inpatient, outpatient, and community-based settings. A structured review of peer-reviewed studies published between 2015 and 2025 was conducted, focusing on clinical outcomes, patient satisfaction, functional recovery, adherence to treatment, and health system efficiency. Evidence indicates that nurseled care models, including nurse-led psychotherapy, medication management, case management, and community follow-up, are associated with significant improvements in symptom control, reduced hospitalization rates, enhanced continuity of care, and high patient satisfaction. Eight figures and three tables are integrated to illustrate care models, outcome pathways, and comparative effectiveness. The findings support the expanding role of psychiatric nurses as autonomous and collaborative providers in mental health care delivery.