Background and Objectives: Health and healthy lifestyles are influenced by a range of factors, including health literacy and media literacy, both of which play important roles in health-related decision-making and behaviors. This study aimed to determine the predictive role of media literacy and demographic factors in health literacy among adolescents aged 15–18 years in Mashhad, Iran.

Materials and Methods: This research was a cross-sectional study with 400 subjects of male adolescents aged 15–18 years in Mashhad, Iran. The data collection tools used in this study included demographic questionnaire, health literacy of adolescent’s questionnaire, and media literacy questionnaire. Data were analyzed by using SPSS 25.0. To examine the associations between demographic characteristics and media literacy with health literacy, a multiple linear regression model was employed.

Results: Approximately 58% of adolescents fell into insufficient levels of health literacy. In contrast, about 60% were in the moderate range for media literacy. Among the demographic variables examined, none showed a statistically significant effect on health literacy, except birth order. Most notably, media literacy emerged as a very strong predictor of health literacy, with a standardized beta coefficient of 0.611 (p<0.001).

Conclusion: Socioeconomic status was not significantly associated with health literacy, whereas birth-order dynamics may play a nuanced role. These findings suggest that integrating media literacy within universal health education may strengthen adolescents’ health information competencies. Given the limited association observed with socioeconomic status, universal media-literacy initiatives may warrant consideration, alongside further examination of family processes. Future research could employ longitudinal designs, multi-method assessments, and evaluate the impact of media-literacy–enhanced health education on health-related outcomes.