BACKGROUND: Household food insecurity and mental disorders are both prevalent conditions among children and adolescents (i.e., youth) in the United States. Although some research has examined the association between the 2 conditions, it is not known whether more severe food insecurity is differently associated with mental disorders in youth. OBJECTIVE: We investigated the association between severity of household food insecurity and mental disorders among children (aged 4-11 y) and adolescents (aged 12-17 y) using valid and reliable measures of both household food security status and mental disorders. METHODS: We analyzed cross-sectional data on 16,918 children and 14,143 adolescents whose families participated in the 2011-2014 National Health Interview Survey. The brief Strengths and Difficulties Questionnaire and the 10-item USDA Household Food Security Survey Module were used to measure mental disorders and food security status, respectively. Multinomial logistic regressions were used to test the association between household food security status and mental disorders in youth. RESULTS: There was a significant linear trend in ORs, such that as severity of household food insecurity increased so did the odds of youth having a mental disorder (P < 0.001). Other selected results included the following: compared with food-secure households, youth in marginally food-secure households had higher odds of having a mental disorder with impairment [child OR: 1.26 (95% CI: 1.05, 1.52); adolescent OR: 1.33 (95% CI: 1.05, 1.68)]. In addition, compared with food-secure households, youth in very-low-food-secure households had higher odds of having a mental disorder with severe impairment [child OR: 2.55 (95% CI: 1.90, 3.43); adolescent OR: 3.44 (95% CI: 2.50, 4.75)]. CONCLUSIONS: The severity of household food insecurity is positively associated with mental disorders among both children and adolescents in the United States. These results suggest that improving household food security status has the potential to reduce mental disorders among US youth.