Objectives: Congenital heart disease (CHD) is a prevalent condition affecting young people that often necessitates complex medical interventions. This study aims to provide a synthesis of existing meta-analyses examining the impact of CHD on the cognitive functioning in children and young people; Methods: A comprehensive literature review was conducted, identifying peer-reviewed meta-analyses from 1 January 1976 to 17 December 2024, focusing on the cognitive outcomes of CHD patients aged 0–24 years. Data extraction covered study details, participant demographics, outcomes, and quality assessments. Quality assessment followed the Scottish Intercollegiate Guidelines Network (SIGN) checklist, and a narrative synthesis was conducted; Results: The narrative synthesis highlighted significant cognitive impairments in children with CHD across domains such as Intelligence Quotient (IQ), executive functions (EF), memory, and alertness. Cognitive impairments were also observed to become worse with increasing age. Furthermore, surgical interventions were found to impact cognitive outcomes, with surgeries at an early age improving survival rates but not entirely mitigating cognitive deficits. Cognitive impairments were more marked in young people assessed at an older age and with a more complex CHD presentation. Conclusions: Children with CHD face persistent cognitive challenges, underscoring the need for early identification and tailored interventions. Routine cognitive assessments and comprehensive care, including educational and psychological support, are crucial for improving neurodevelopmental outcomes. Future research should focus on longitudinal studies to track cognitive development and explore effective rehabilitation programs.