<p>This cross-national study investigates how psychopathy, narcissism, and fear of missing out (FoMO) influence online political participation, and how cognitive ability moderates these associations. Drawing on data from the United States and seven Asian countries, the findings reveal that individuals high in psychopathy and FoMO are consistently more likely to engage in online political activity. While narcissism is also linked to participation, this relationship emerges in only three of the eight countries. Conversely, higher cognitive ability is uniformly associated with lower levels of online political participation. Notably, the relationship between psychopathy and participation is stronger among individuals with lower cognitive ability in five countries, suggesting that those with both high psychopathy and low cognitive ability are the most actively involved in online political engagement. These findings underscore the nuanced interaction between dark personality traits, FoMO, and cognitive functioning in shaping digital political engagement across diverse socio-political contexts.</p>