The breadth of available non-pharmacological interventions for autistic children, with varying evidence for efficacy summarised in multiple systematic reviews, creates challenges for parents, practitioners, and policymakers in navigating the research evidence. In this article, we report the findings of an umbrella review of 58 systematic reviews of non-pharmacological interventions for autistic children (aged 0-12 years). Positive therapeutic effects were identified for "Behavioural interventions," "Developmental interventions," "Naturalistic Developmental Behavioural Interventions," "Technology-based interventions," and "Cognitive Behaviour Therapy" across several child and family outcomes. Positive effects for certain practices within "Sensory-based interventions" and 'other' interventions were limited to select child and family outcomes. Both inconsistent and null intervention effects were found for "Treatment and Education of Autistic and related Communication-handicapped Children," and "Animal-assisted interventions" across outcomes. The possible influence of child (chronological age, core autism characteristics, and related skills) and delivery (agent, mode, format, and amount) characteristics on intervention effects was rarely examined, and inconsistent where reported. Twenty-seven systematic reviews (47%) were rated as 'high' quality. Few systematic reviews examined children's participation and quality of life or adverse effects. The findings highlight the need for individualised evidence-based decision-making when selecting interventions for autistic children.