Background <p>The pervasive nature of social media has given rise to the phenomenon of fear of missing out (FoMO), which poses significant challenges to the mental health of children. By drawing on an individual-centered approach, this study aims to provide a nuanced understanding of FoMO.</p> Methods <p>We delved into the evolving nature of FoMO patterns among 541 Chinese primary school students within a one-year interval. Employing Latent Profile Analysis (LPA) and Random Intercept Latent Transition Analysis (RI-LTA), we uncovered three distinctive profiles of FoMO: Social Sentinels, Worry Warriors and Untroubled Buddies. To predict transitions between these profiles, we examined anxiety and mindfulness. We also investigated the relationship between two related outcomes and latent transitions.</p> Results <p>The results revealed that the Untroubled Buddies profile was relatively stable, while the Social Sentinels and Worry Warriors profiles showed more frequent transitions over time. Regarding the antecedents, our findings demonstrated that primary school students with high anxiety were more likely to be categorized under the Social Sentinels and Worry Warriors profiles, increasing their risk of transitioning from the Untroubled Buddies profile to the other two profiles over time. Regarding the associations with outcomes, significant differences emerged among the three profiles in terms of emotional and behavioral problems as well as depression at three measurement points.</p> Conclusions <p>Identifying different FoMO profiles among primary school students and understanding the nature of transitions between these profiles have implications for developing targeted interventions to mitigate FoMO risks among primary school students, as well as preventing individuals from transitioning into profiles associated with higher risks of emotional and behavioral problems and depression.</p>