Purpose: Physical development is an integral part of a child’s overall development. Evidence suggests that physical development and physical activity are positively correlated with positive academic outcomes in elementary and secondary school students. However, research on physical development among preschool-age children lags behind. Therefore, the purpose of the current study was to assess the relationships between physical development and other aspects of development related to school readiness among 3- to 5-year-old children. Method: Teacher ratings of physical, cognitive, language, social–emotional, and literacy development were collected for 172 preschool students. Group differences were assessed using analysis of variance, and relationships among development scales were examined with Pearson correlations. Results: Pearson correlations indicate ratings of physical development are significantly and positively correlated with ratings on the other four development scales. Discussion/Conclusion: Findings support the importance of physical development as an aspect of school readiness. Practical implications and future research are discussed.