This mixed-methods study examines the impact of social media use on body image and mental health among Bangladeshi youth, focusing on gender and age differences. Platforms like Instagram and Snapchat significantly contribute to body dissatisfaction, particularly among females aged 15-18. The findings reveal a strong correlation between increased social media use, heightened self-comparison, reduced self-esteem, and mental health challenges, including anxiety and depression. Peer pressure, social comparison, and negative online interactions further intensify these effects. To address these issues, the study advocates for media literacy programs to help youth critically engage with social media, body positivity campaigns to challenge unrealistic beauty standards, and family engagement to foster supportive environments. These interventions aim to promote critical social media engagement and resilience in youth, ultimately improving their mental well-being in Bangladesh.