Social media has revolutionized information sharing, yet it has also accelerated the spread of misinformation, particularly among teenagers who are highly active on digital platforms. This study, conducted at Talangan Integrated National High School (TINHS), examines how social media habits, peer influence, and digital engagement contribute to the spread of misinformation. Using a quantitative research design, data were collected from Grade 11 learners through structured surveys assessing social media usage, susceptibility to misinformation, and peer influence. A mathematical model based on the Susceptible-Infected-Recovered (SIR) framework was applied to analyze the transmission patterns of misinformation within digital networks. The results indicate a strong correlation between high social media usage and increased susceptibility to misinformation. Peer influence emerged as a critical factor in reinforcing false beliefs, with students more likely to trust and share information endorsed by their peers. The findings align with existing studies, highlighting the role of social conformity in misinformation spread. Furthermore, the mathematical model demonstrated that misinformation dissemination follows predictable patterns, where higher exposure and engagement rates increase its spread, while fact-checking and digital literacy interventions help mitigate its effects. Based on these insights, the study recommends the integration of fact-checking tools on social media platforms, the implementation of school-based media literacy programs, and peer-led initiatives to promote responsible digital engagement. These measures can significantly reduce misinformation vulnerability among teenagers. By fostering critical thinking and media literacy, educational institutions and policymakers can equip young individuals with the skills necessary to navigate the digital landscape responsibly.