TikTok has rapidly become one of the most popular social media platforms, and, thus, scholars should pay attention to its association with users’ mental health. Our aim was to synthesize and evaluate the association between problematic TikTok use and mental health. We applied the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines in our review. The review protocol was registered with PROSPERO (CRD42024582054). We searched PubMed, Scopus, Web of Science, PsycINFO, ProQuest, and CINAHL until September 02, 2024. We identified 16 studies with 15,821 individuals. All studies were cross-sectional and were conducted after 2019. Our meta-analysis showed a statistically significant positive association between TikTok use and depression (β = 0.321, 95% confidence interval [CI]: 0.261 to 0.381, p < 0.001), and anxiety (β = 0.406, 95% CI: 0.279 to 0.533, p < 0.001). Also, we found a positive association between TikTok use and body image issues, poor sleep, anger, distress intolerance, narcissism, and stress. Our findings suggest that problematic TikTok use has a negative impact on several mental health issues. Given the high levels of TikTok use especially among young adults, our findings are essential to further enhance our understanding of the impact of TikTok use on mental health. Finally, there is a need for further studies of better quality to assess the impact of problematic TikTok use on mental health in a more valid way.