This study aimed to systematically review the current body of research on parent and caregiver mental health literacy. Electronic databases were searched in January 2018 with 21 studies meeting inclusion criteria. A narrative synthesis of quantitative and qualitative studies was conducted. Findings across studies suggest that parents and caregivers had limited mental health knowledge. Factors associated with help-seeking included cultural and religious beliefs, financial and knowledge barriers, fear and mistrust of treatment services, and stigma. Notable limitations include non-representative samples, cross-sectional research designs, and use of inconsistent and non-validated study measures. Research would benefit from more diverse samples, an increased focus on prevention, and controlled trials of educational programmes targeting mental health literacy.