Background: Evidence-based interventions are essential for school-aged children with intellectual disabilities to facilitate development and promote future independence. Methods: Using a PRISMA approach, systematic screening of five databases was undertaken. Original randomised controlled studies with psychosocial-behavioural interventions were included where participants were school aged (5-18 yrs) with documented intellectual disability. Study methodology was assessed using the Cochrane RoB 2 tool. Results: Two thousand three hundred and three records were screened with 27 studies included. Studies mainly included primary school participants with mild intellectual disabilities. Most interventions focused on intellectual skills (e.g., memory, attention, literacy and mathematics) followed by adaptive skills (e.g., daily living, communication, social and education/vocation) and some focused on a combination of these. Conclusion: This review highlights the gap in evidence-base for social, communication and education/vocation interventions with school-aged children with moderate and severe intellectual disability. Future RCTs that bridge this knowledge gap across ages and ability are required for best practice.