The pervasive influence of social media has significantly impacted the mental health and well-being of young adults, particularly through increased social media addiction (SMA) and social appearance anxiety (SAA). Our study investigates the relationship between social media addiction and social appearance anxiety among young adults, highlighting the interplay between compulsive social media use and concerns about physical appearance. A sample of 549 undergraduate students from Turkey, including 339 females and 210 males, completed the Social Media Addiction Scale (SMAS) and the Social Appearance Anxiety Scale (SAAS). Data were analyzed using correlation, independent t-tests, and linear regression to explore the relationships and differences between variables. Our study found significant relationships between SMA and SAA, with higher levels of addiction linked to increased appearance anxiety. Social comparison tendencies and photo-editing behaviors were also associated with higher SMA and SAA. No significant gender differences were observed, suggesting a universal impact of social media on these psychological issues. The findings underscore the intertwined nature of SMA and SAA, emphasizing the need for comprehensive interventions that address both aspects to improve mental health outcomes. Promoting positive self-comparisons and reducing photo-editing behaviors online can help mitigate the negative effects of social media use on young adults’ mental well-being.