The purpose of this study was to specify the development of and links between executive functioning and theory of mind during middle childhood. One hundred four 7- to 12-year-old children completed a battery of age-appropriate tasks measuring working memory, inhibition, flexibility, theory of mind, and vocabulary. As expected, spatial working memory and flexibility increased significantly with age, especially after 7 years. Moreover, flexibility predicted social understanding over and above the effects of age, vocabulary, working memory, and inhibition. Together, these findings highlight improvements in and tight relations between complex aspects of executive functioning and theory of mind during middle childhood and suggest that executive functioning and theory of mind are linked beyond their emergence in early childhood.