<p>Current National Institute for Health and Care Excellence (NICE) guidelines recommend family interventions for children and adolescents with psychosis. However, the evidence to support this has not been fully synthesised to date. This meta-analytic review investigated whether family interventions are effective in reducing psychosis symptoms and improving functioning among children and adolescents with psychosis. We included studies which (1) employed a controlled study design to examine the effectiveness of a family intervention, (2) only included children or adolescents with psychosis, and (3) assessed psychosis symptoms and/or general functioning. PubMed, Scopus, Web of Knowledge, OVID, CNKI, EBSCO and Cochrane CENTRAL were searched on the 19th of March 2024, supplemented by grey literature searches. Study quality was assessed with the Cochrane Risk of Bias Assessment Tools. Bayesian meta-analyses were conducted to examine changes in symptoms and functioning. Four studies (<i>n</i> = 111) met inclusion criteria. All studies assessed the effectiveness of different psychoeducation-based family interventions. The meta-analyses showed no significant effect of family interventions on psychosis symptoms (pooled effect size = -0.93, 95% CrI [-2.77, 0.90]) or functioning (pooled effect size = 0.90, 95% CrI [-1.07, 2.70]) and indicated weak evidence in favour of the null hypotheses. We did not find evidence of a significant benefit of family interventions on psychosis symptoms or functioning in children and adolescents with psychosis. All included studies had significant methodological issues, which may have introduced bias. These results highlight a lack of evidence of the effectiveness of family interventions in children and adolescents with psychosis.</p>