Based on data for N = 2,756 children (1,410 girls; Mage = 8.10 years) from 16 data sets spanning five nations, this study investigated relations between national gender disparities and children's beliefs about gender and academic subjects. One national-level gender disparity involved inequalities in socioeconomic standing favoring adult males over females (U.N. Human Development Index). The other involved national-level gaps in standardized math achievement, favoring boys over girls (Trends in International Mathematics and Science Study Grade 4). Three novel findings emerged. First, girls' results from a Child Implicit Association Test showed that implicit associations linking boys with math and girls with reading were positively related to both national male advantages in socioeconomic standing and national boy advantages in Trends in International Mathematics and Science Study. Second, these relations were obtained for implicit but not explicit measures of children's beliefs linking gender and academic subjects. Third, implicit associations linking gender to academic subjects increased significantly as a function of children's age. We propose a psychological account of why national gender disparities are likely to influence children's developing implicit associations about gender and academic subjects, especially for girls. (PsycInfo Database Record (c) 2024 APA, all rights reserved).