Background and aims <p>Smartphone addiction is a global problem, especially among college students, and has brought many kinds of harm to college students. Previous studies have confirmed the risk factors of smartphone addiction, but the effects of social anxiety and depressive symptoms on smartphone addiction and the potential mediating mechanisms have not been fully explored. The focus of this study is to clarify the influence of social anxiety on smartphone addiction and the mediating role of depressive symptoms in this relationship to help college administrators formulate smartphone addiction prevention programs for college students.</p> Methods <p>This study conducted a questionnaire survey on 3,379 college students from different universities in China. They completed the Social Anxiety Scale, Beck Depression Inventory-II, and Smartphone Addiction Scale. Then, This study used the SPSS Macro program PROCESS v 4.0 to test the mediation model.</p> Results <p>Statistical analysis showed that social anxiety, depressive symptoms, and smartphone addiction were all positively correlated. We further found that social anxiety had a predictive effect on smartphone addiction, and depressive symptoms played a complete mediating role in the relationship between social anxiety and smartphone addiction among college students.</p> Discussion and conclusion <p>This research emphasizes the importance of considering social anxiety and depressive symptoms when studying the underlying mechanisms of smartphone addiction among college students, thereby offering valuable insights for devising intervention strategies aimed at mitigating addictive behaviors in this population.</p>