Emerging evidence suggests a cross-sectional association between food insecurity (FI) and disordered eating among adults, while evidence among adolescents is limited. Longitudinal research is needed to elucidate the temporality of this relationship and clarify whether the association differs by age. Three waves of prospective data came from 1813 participants in the Project EAT (Eating and Activity in Teens and Young Adults) cohort study. Data were collected at five-year intervals, with the baseline survey in 1998-1999 (EAT-I; M = 14.9 years) and follow-up surveys in 2003-2004 (EAT-II; M = 19.5 years) and 2008-2009 (EAT-III; M = 24.9 years). Severe FI was assessed as any past-year hunger with one item from the U.S. Household Food Security Survey Module, and a range of disordered eating behaviors were self-reported. Associations adjusted for sociodemographic characteristics were examined with generalized estimating equations. Effect modification by age was also tested. Cross-sectionally, severe FI was significantly associated with greater prevalence of all disordered eating behaviors examined, with the strongest associations observed for extreme weight-control behaviors (prevalence ratio [PR] = 1.49, 95% confidence interval [CI]: 1.13-1.95) and binge eating (PR = 1.49, 95% CI: 1.04-2.12). Longitudinally, severe FI significantly predicted 1.41 (95% CI: 1.05-1.90) times greater prevalence of binge eating five years later after accounting for prior binge eating. Effect modification by age indicated a stronger cross-sectional association between severe FI and unhealthy weight-control behaviors among younger participants. Results support a cross-sectional link between severe FI and disordered eating and provide longitudinal evidence suggesting severe FI is a risk factor for binge eating.