Neurodevelopmental difficulties can have a substantial impact on children’s lives and often have lasting effects in adult life. The scientific study of the causes and consequences of neurodevelopmental difficulties has arguably been slowed by the overreliance on case-control designs, which fail to capture the overlap across different neurodevelopmental disorders and the heterogeneity within them. The work presented in this thesis applies a transdiagnostic framework to large developmental datasets to advance our understanding of neurodevelopmental diversity. Three empirical studies were conducted with a cohort of children with a range of diagnosed and undiagnosed needs. The first study explored the interrelationships between language, communication, cognitive, and behavioural difficulties using network science (Chapter I). A subsequent study investigated how children vary in their relative strengths and weakness across these domains, and how this variation relates to socio-emotional functioning, academic skills, and neural white matter organisation (Chapter II). The third study compared the pattern of interrelationships between cognitive and academic skills observed in this cohort to those found in a community sample (Chapter III). Collectively, the studies presented in this thesis demonstrate the value of studying neurodevelopmental diversity transdiagnostically. I argue that the field needs to move away from studying groups of children with restricted difficulties and dedicate more effort towards understanding how multiple developmental factors interact to shape individual trajectories over developmental time.