The cultural gap—defined as the divergence in values, attitudes, identity, and lifestyles between different generations—has emerged as one of the key social challenges in contemporary societies, particularly in the context of rapid technological change. The widespread adoption of virtual social networks has triggered profound shifts in cultural norms and intergenerational relationships. This study investigates the impact of social media use on the cultural gap between generations, emphasizing the mediating role of media literacy among youth in Tehran during the 2023–2024 academic year. Employing a survey methodology, the research utilized both standardized and researcher-developed questionnaires for data collection. The study population comprised undergraduate and graduate students from various universities in Tehran. A stratified sampling method was applied to select a sample of 384 participants. Data were analyzed using SPSS and SmartPLS software, with the conceptual framework evaluated through path analysis and structural equation modeling (SEM). The results revealed a significant and positive relationship between variables such as frequency, duration, and satisfaction with social media use and the intergenerational cultural gap. Furthermore, media literacy played a mediating role by mitigating the direct influence of social media use on this gap. The findings suggest that enhancing media literacy can serve as a strategic approach to narrowing the cultural divide between generations and should be prioritized by cultural and educational policymakers.