Fine motor skills and executive function are two examples of domain-general skills. Both are correlates of arithmetic and reading ability, and have been identified as predictors of school readiness. Little research has simultaneously assessed the influence of both these skills as predictors of academic abilities. Current evidence suggests their role as predictors lessens once children enter school. Importantly this limited research often disregards the role of well-established domain-specific predictors. In this large-scale longitudinal study (N = 569) we evaluate the role of fine motor skills, executive function, and domain-specific skills at 5-years as predictors of arithmetic and reading skills at 6-years. Fine motor skills and executive function at school entry correlate strongly with each other, with the longitudinal association between fine motor skills and performance in reading and arithmetic completely accounted for by variance shared with executive function skills. However, neither executive function nor fine motor skills account for variance in reading or arithmetic after controlling for more proximal predictors of these skills. If either fine motor or executive function skills promote learning in school, it seems their effects on reading and arithmetic development may be mediated by more proximal skills. From an applied perspective, this study casts doubt on the usefulness of motor skills as a target for intervention to support academic performance, at least after school entry. It also highlights the need to examine more closely the relations between domain-general and domain-specific skills in early development.