Background: Children and young people with intellectual disability have poor healthcare and are at risk of patient safety events due to lack of staff training and consensus on competencies for safe and quality care. For the adoption of reasonable adjustments in mainstream paediatric healthcare clinical competencies needed to be adapted to an existing patient safety education framework. Methods: Thirteen experts in intellectual disability health and patient safety participated in an eDelphi survey aimed at reaching consensus on core competencies required of the paediatric healthcare workforce. Four rounds were completed with descriptive and thematic analyses undertaken. Results: Consensus was achieved for 120 competencies across seven domains. Results highlighted the need for adaptations in all the domains, particularly communication, working safely and specific areas unique to this population. Conclusion: An adapted framework that addresses competencies for safe and quality care that included reasonable adjustments is critical for improving care for this population.