<p>Despite the well-established importance of executive function (EF) in learning and school performance, the literature lacks a quantitative synthesis of the association between genetic variants and EF, as well as an examination of its potential heterogeneity. This meta-analytic investigation addressed this gap by quantifying the association between genetic variants and EF across childhood and adolescence and examining factors that may be related to its heterogeneity, including sample characteristics (age, sex, and cultural background), EF components (hot and cool EF), measures (cognitive tasks and caregiver-reported scales), and biochemical pathways. Systematic searches were conducted across four databases using three sets of conceptually distinct keywords. The final meta-analysis incorporated 19 candidate-gene and genome-wide association studies, which provided 61 effect sizes derived from 16 independent samples (total <i>N</i> = 12,200; range of sample size: 20 to 8,707). The three-level meta-analysis revealed a significant association between genetic variants and EF in children and adolescents (Hedges’s <i>g</i> = 0.32, <i>p</i> &lt; .001). Moderating analyses further showed that the gene-EF relation varied by age and biochemical pathways of genetic variants. Specifically, stronger associations were observed among older participants and in relation to lipid metabolism. This study provides meta-analytic evidence synthesizing the association between genetic variants and individual differences in EF among children and adolescents. The findings suggest that, although individual differences in EF are partly biologically informed, particularly as children grow, the overall strength of this association was small to moderate.</p>