 This systematic review has highlighted the need for further research into the role of service users and caregivers in mental health system strengthening in low and middle-income countries, LMICs. It has also suggested several key recommendations for future research, such as evaluating the effectiveness of service user and caregiver involvement in mental health system strengthening, developing robust methodologies for assessing the impact of service user and caregiver involvement, and conducting longitudinal studies to measure the long-term outcomes of service user and caregiver involvement. This article was authored by Maya Semrao, Heidi Lemp, Roxanne Kinjad, and others.