The proliferation of social media (SM) platforms has made them an integral part of our daily lives, significantly shaping how we interact and engage with the world. While SM offers benefits such as social connectedness and support, its impact on the psychological health and well-being of young individuals has both positive and negative dimensions. Understanding these effects is essential to developing strategies for mitigating the adverse outcomes associated with its use. A systematic literature review was conducted to explore the influence of SM usage on the mental health and well-being of young adults aged 18 to 35. Drawing insights from 25 publications across three databases, the study identified common themes related to SM’s effects on this demographic. The findings reveal a correlation between SM use and mental health outcomes, with benefits including enhanced social support but also risks such as depression, anxiety, low self-esteem, and increased vulnerability to cyberbullying. These results highlight the urgent need for targeted interventions to address the negative consequences of SM on the mental health and overall well-being of young adults.