Curiosity is a potential risk factor for electronic cigarette (e-cigarette) use, which has increased considerably among US youth in recent years. We examined the relationship between curiosity about e-cigarettes and perceived harm, comparative addictiveness, and e-cigarette advertisement exposure. Data came from the 2014 National Youth Tobacco Survey, a nationally representative survey of U.S. middle and high school students. In 2014, 2.5% of middle school and 9.2% of high school students currently used cigarettes, while 3.9% of middle school and 13.4% of high school students reported current e-cigarette use. Among never e-cigarette users (n=17,286), descriptive statistics assessed curiosity about e-cigarettes by combustible tobacco use, sex, race/ethnicity, and school level. Associations between curiosity and perceived harm (absolute and comparative to cigarettes), comparative addictiveness, and e-cigarette advertising exposure were explored using multivariate models in 2015. Among youth who never used e-cigarettes, 25.8% reported curiosity about e-cigarettes. Higher levels of perceived absolute harm and comparative harm were associated with lower levels of curiosity, while no association was observed between comparative addictiveness and curiosity. Among never combustible tobacco users, the odds of high curiosity were greater among non-Hispanic blacks (odds ratio (OR): 1.39; 95% confidence interval (CI):1.02–1.88), Hispanics (OR=1.79; 95% CI:1.48–2.16), and non-Hispanic ‘Other’ (OR=1.47; 95% CI:1.15–1.89) race/ethnicities than non-Hispanic whites. One-quarter of middle and high school students who have never used e-cigarettes are curious about the products, with greater curiosity among those with lower perceptions of harm from these products. These findings may help inform future strategies aimed at reducing curiosity about e-cigarettes among youth.