This study of 241 parent–child dyads from the United Kingdom (N = 120, Mage = 3.92, SD = 0.53) and Hong Kong (N = 121, Mage = 3.99, SD = 0.50) breaks new ground by adopting a cross-cultural approach to investigate children's theory of mind and parental mind-mindedness. Relative to the Hong Kong sample, U.K. children showed superior theory-of-mind performance and U.K. parents showed greater levels of mind-mindedness. Within both cultures parental mind-mindedness was correlated with theory of mind. Mind-mindedness also accounted for cultural differences in preschoolers’ theory of mind. We argue that children's family environments might shed light on how culture shapes children's theory of mind. Copyright © 2017 The Authors.