Abstract Introduction E-cigarette cessation intervention research is limited. Young adult e-cigarette use and cessation is particularly nuanced, given various user profiles (ie, polytobacco use, co-use with marijuana) warranting different intervention approaches. Methods The current study is an analysis of baseline survey data (collected September–December 2018) among 1133 young adult (aged 18–34) e-cigarette users in a 2-year longitudinal study. We examined (1) e-cigarette user profiles (ie, e-cigarette only; e-cigarette/other tobacco; e-cigarette/marijuana; e-cigarette/other tobacco/marijuana) and (2) correlates of readiness to quit e-cigarette use in the next 6 months and past-year e-cigarette quit attempts. Results In this sample (Mage = 23.91, 47.3% male, 35.5% sexual minority, 75.2% White, 13.7% Hispanic), e-cigarette user profiles were as follows: 16.8% e-cigarettes-only, 23.4% e-cigarette/other tobacco, 18.0% e-cigarette/marijuana, and 41.8% e-cigarette/other tobacco/marijuana. Multinomial logistic regression (referent: e-cigarette-only use) indicated that all polyuse groups were more likely to use high-nicotine e-liquids (containing ≥9 mg of nicotine). Other predictors included e-cigarettes/other tobacco users being older and male; e-cigarettes/marijuana users using closed systems; and e-cigarettes/other tobacco/marijuana users being sexual minority (p’s < .01). Readiness to quit e-cigarettes and past-year quit attempts were reported by 20.8% and 32.3%, respectively. Per multilevel regression, readiness to quit and quit attempts correlated with using fewer days, high-nicotine e-liquids, and closed systems, but not marijuana, as well as being heterosexual and Black (vs White); readiness to quit also correlated with being single; past-year quit attempts correlated with other tobacco use and being Hispanic. Conclusions Young adult e-cigarette users demonstrate distinct user profiles and cessation-related experiences that should be considered in developing cessation interventions. Implications The vast majority of young adult e-cigarette users use other tobacco products and marijuana. Unfortunately, few reported readiness to quit or attempting quit. Moreover, certain subgroups (eg, sexual/racial/ethnic minorities) are more likely to be ready or attempt to quit, but may not be successful. Vaping cessation interventions must attend to these nuances.