PurposeInformational use of social media facilitates political engagement. Yet, there is also evidence of the perils of frequent political engagement in misinformation propagation. This study aims to examine the association between online political engagement, perceived exposure to misinformation, individuals’ cognitive characteristics and misinformation sharing.Design/methodology/approachIn this paper, online surveys were conducted in Kenya, Nigeria and South Africa (Study 1) and the United States (Study 2).FindingsStudy 1 finds that online political engagement is positively associated with perceived exposure to and sharing of misinformation. Mediation analyses suggest that the relationship between online political engagement and misinformation sharing is mediated by perceived exposure to misinformation. Further, the likelihood of sharing misinformation is found to increase at higher levels of online political engagement, but those with low need for cognition (NFC) are more vulnerable to such sharing. Study 2 explores cognitive ability in place of NFC. The results follow similar patterns as Study 1 – online political engagement is linked to misinformation sharing via higher perceived exposure to misinformation. The authors also find that the tendency to share misinformation increases with frequent exposure to misinformation but those with lower cognitive ability are more prone to such sharing.Originality/valueIn both contexts, the data show that perceived exposure to misinformation mediates the relationship between online political engagement and misinformation sharing and those with low NFC and cognitive ability are more vulnerable. Overall, the findings offer insight into the mechanisms of political engagement and sharing misinformation.