PurposeThe impacts of passive (i.e., browsing) versus active (i.e., engagement) use of social media on e-cigarette use among youth have been understudied in existing literature. This study examines how passive and active use of social media are differentially associated with e-cigarette use among youth and how risk perceptions mediate these associations. MethodsPooled data from the 2021 and 2022 National Youth Tobacco Survey (N=48,704, aged 11–19) were used. Weighted structural equation models were employed to estimate the associations between passive and active social media use and youth e-cigarette use. ResultsBoth passive and active social media use were associated with higher odds and more days of e-cigarette use among youth. E-cigarette risk perceptions mediated the associations between active use and both the likelihood of ever using e-cigarettes and the number of days of use. Risk perceptions mediated the association between active, but not passive, use and the number of days of e-cigarette use. Compared to passive use, active use was overall associated with higher odds and more days of youth e-cigarette use. DiscussionThe findings suggest that public health efforts should distinguish between passive and active social media use when designing and executing interventions. Attention and efforts should also be directed towards understanding the distinct indirect effects of passive and active social media use through risk perceptions. These findings advance our theoretical understanding of the role of different types of social media use and offer significant practical insights for interventions.