Background: Poor oral hygiene is a prevalent public health concern in children, leading to dental caries and gingivitis which can be prevented. Schools are recognized as strategic settings for delivering oral health education (OHE), which provide continuous access to children during their formative years.In this systematic review we aimed to evaluate the effectiveness of school-based oral health education programs in improving children’s oral hygiene, knowledge, and related behaviors. Methods: A systematic search was conducted in PubMed, Scopus, Web of Science, and Google Scholar to identify original peer reviewed studies to assess school-based OHE interventions for children aged 18 years or younger. We include studies measured at least one oral health outcome (plaque index, brushing frequency, caries incidence). Risk of bias was assessed using the Cochrane RoB 2 tool for randomized trials and ROBINS-I for non-randomized studies. A qualitative synthesis approach was used. Results: Ten studies (8 RCTs and 2 quasi-experimental) with a total sample of 5,539 children were included. Interventions differ in duration, educator type (peer, teacher, dental professional), and theoretical framework. Most studies show significant improvements in oral hygiene behaviors, plaque levels, and knowledge post-intervention. Peer-led approaches and programs which incorporate behavioral theories showed greater effectiveness in behavior change. Reinforcement and educator involvement were key factors contributing to sustained outcomes. Conclusion: School-based oral health education programs are effective to enhance children’s oral hygiene knowledge and practices. Programs involving interactive methods, behaviors, and consistent reinforcement are more likely to produce lasting improvements. Integration of these programs into school curricula is recommended to promote long-term oral health in children.