Children with single-suture craniosynostosis (SSC) are increasingly considered to be at high risk of adverse neurodevelopmental outcomes. This systematic review aimed to synthesise and critically appraise the existing literature on the neurodevelopmental features of SSC, with particular attention to methodological quality. A total of 33 articles based on 27 cohorts met inclusion criteria. In the context of variable methodological design and quality, most neurodevelopmental studies indicated that children with SSC are at increased risk for difficulties in cognitive, language, and motor domains during infancy (both pre- and post-surgery) and childhood. Limited information exists on factors influencing outcome.