Abstract Purpose This is the first comprehensive review of empirical research that investigated the association between receipt of child welfare services and adult mental health outcomes. The review summarised the results of studies about mental health outcomes of adults with a history of child welfare involvement. Methods A scoping review methodology was used to search five electronic databases (MEDLINE, EMBASE, PsychINFO, IBSS, Social Policy and Practice). Studies were included if they examined any child welfare exposure (including receipt of services while remaining at home/being placed in care) and adult mental health status. Results In total 4591 records were retrieved, of which 55 met the eligibility criteria. Overall, receipt of child welfare services was associated with an increased risk of adult mental ill-health, suicide attempt and completed suicide. Results regarding potential moderating factors, such as gender and care-related experiences, were mixed. Relatively few studies investigated the reasons for requiring child welfare services, the experience of abuse or neglect or the adult outcomes of child welfare service users who remained in their own homes. Mental ill-health was defined and measured heterogeneously and details about the nature and type of welfare service utilisation were lacking. Conclusion There is a need for detailed, longitudinal studies to better understand the relative contribution of pre-existing adversity versus experiences during and after exposure to child welfare services on adult mental health outcomes. More standardised measures of mental ill-health and greater detail from authors on specific care exposure are also needed.