Although digital transformation has expanded classroom technology access, the integration of ethical development within digital learning environments remains limited. This study investigates the relationship between executive functions and ethical digital citizenship among primary school students aged 6–12 years. Key contributing factors examined include smart education, digital literacy, ethical competency, teacher agency, institutional support, and executive function. Empirical data were collected from 387 primary school teachers and administrators within the Office of the Basic Education Commission network via online and printed questionnaires, capturing educators’ professional observations and proxy-reports of their students’ behavior. Using partial least squares structural equation modeling (PLS-SEM), the study tested seven hypotheses. Results indicate that smart education directly influences digital literacy, a relationship significantly moderated by teacher agency. Furthermore, digital literacy directly impacts ethical competency, with institutional support serving as a critical moderator. Finally, executive functions demonstrated a significant, direct impact on students’ ethical competency. By highlighting the interconnected roles of these six factors, this study provides a novel, evidence-based framework that policymakers can utilize to effectively foster ethical digital citizenship among young Thai learners.