Background: People with neurodevelopmental disabilities are frequently prescribed or administered psychotropic medication, particularly to manage behaviours of concern. Reducing inappropriate psychotropic use has been the target of international research and policy for several decades. Methods: Six electronic databases were searched for interventions to reduce inappropriate prescribing or administration of psychotropics in this population. Results: Sixteen pre-post studies were included in this review. Meta-analysis showed a significant reduction in the number of participants receiving psychotropics for medication review, multi-component interventions, workplace training, and organisational guidelines and policies (risk ratio [RR] = 0.52, 95% CI [0.43, 0.62], p < 0.00). Subgroup analysis showed significant reductions with all interventions, with no apparent differences in reduction size between intervention types. Conclusion: Interventions reduced psychotropic use in a meta-analysis of pre-post studies. However, potential bias and high heterogeneity suggest that randomised controlled trials (RCTs) are needed for more definitive conclusions.