This research proposed and examined a theoretical model that state boredom leads to a motivation to seek meaningfulness, which promotes the engagement of social comparison. We conducted five studies to test our hypothesis. Specifically, Study 1 and Study 2 found that state boredom increased social comparison preference. Study 3 promoted ecological validity by adopting actual social comparison information-seeking behavior. At the same time, an alternative explanation that state boredom increased information preference regardless of content was ruled out. Study 4 assessed and verified motivation to seek meaningfulness as the psychological mechanism underlying the effect. This study also found that people with different self-construals differed in the amount of increase in the sense of meaningfulness obtained from social comparison. Study 5 adopted a moderation-of-process design to further verify the mediating role of motivation to seek meaningfulness. In conclusion, our findings reveal the impact of state boredom on social comparison and its underlying mechanisms, which contributes to the further understanding of state boredom.