In recent years, the pervasive use of social media platforms has raised concerns about its impact on mental health. This review critically examines the existing literature to elucidate the intricate relationship between social media addiction and mental health. Drawing upon empirical evidence, theoretical frameworks, and conceptual models, this article discusses the various dimensions of social media addiction, its prevalence rates, associated psychological factors, and its implications for mental well-being. Furthermore, it explores the bidirectional nature of the relationship, highlighting how pre-existing mental health conditions can contribute to social media addiction, while excessive usage of social media platforms can exacerbate mental health problems. The review also identifies potential mechanisms underlying this relationship, such as social comparison, fear of missing out (FOMO), cyberbullying, and sleep disturbances. Moreover, it discusses the role of individual characteristics, socio-cultural factors, and platform features in influencing susceptibility to social media addiction and its impact on different aspects of mental health, including depression, anxiety, loneliness, self-esteem, and body image concerns. Finally, the review concludes with implications for research, clinical practice, and public health interventions aimed at mitigating the adverse effects of social media addiction on mental well-being.