Waterpipe tobacco smoking is a public health concern that poses many of the same health risks as cigarette smoking, especially among young adults--a subpopulation characterized by the highest prevalence of waterpipe tobacco smoking. Nevertheless, it remains understudied relative to other forms of tobacco use. We examined sociodemographic, behavioral and cognitive factors associated with young adults' motivation to quit waterpipe smoking using a theory-informed approach. We completed a secondary analysis of baseline data on waterpipe tobacco smoking beliefs and behavior collected from 349 US young adults aged 18-30 years. We analyzed sociodemographics, tobacco use and cessation behaviors and perceptions, and theory-related constructs associated with motivation to quit waterpipe tobacco smoking using linear regression. Overall, participants reported low motivation (mean = 2.68, SD = 1.56, scale range 1-7) and high self-efficacy (mean = 5.12, SD = 1.79) to quit waterpipe tobacco smoking. In multivariable analysis, prior quit attempts ([beta] = 1.10, P < 0.01), greater perceived risks of waterpipe tobacco smoking ([beta] = 0.42, P < 0.01) and increasingly negative attitudes toward waterpipe tobacco smoking ([beta] = 0.29, P < 0.01) were associated with higher motivation to quit. These findings highlight the importance of those factors as potential cessation determinants. These findings can help guide the development and refinement of interventions targeting young adult waterpipe tobacco smoking.