Household food insecurity is associated with youth behavioral problems, yet few studies have examined potential mechanisms that underline this association, particularly among adolescents. The Family Stress Model (FSM) states that food insecurity potentially impacts adolescent psychosocial adjustment indirectly through its effects on parental psychological functioning and parenting. The current study examined data from the Children, Welfare, and Families study (N = 687, 53% female, Mage of child at baseline = 11.74 years, SD = 1.39) to determine whether household food insecurity at the beginning of adolescence predicts later behavioral outcomes and whether that association is mediated through caregiver depression and caregiver–adolescent relationship quality. Caregivers completed measures of past-year household food insecurity, current self-reported depressive symptoms and adolescent behavior problems, while adolescents completed a measure of current caregiver–adolescent relationship quality. A serial multiple mediator model, controlling for baseline values of mediators, outcomes, and relevant demographic covariates, indicated a significant total indirect effect, whereas the total direct effect was not significant. Significant indirect effects through both caregiver depression and caregiver–adolescent relationship quality were also found. These results are the first to explicitly examine the FSM with respect to household food insecurity and to demonstrate the indirect effects of food insecurity on adolescent adjustment. The findings indicate the need to improve food security and address subsequent intra- and inter-personal difficulties among low-income families that contribute to behavioral problems among adolescents facing household food insecurity.