Objectives Household food insecurity is almost four times more prevalent among adolescents than among older adults in Canada, and it adversely affects their health. Our objective was to describe the sociodemographic and geographic patterning of household food insecurity among adolescents. Methods Our analytic sample comprised all 12–17-year-old respondents to the 2017–2018 Canadian Community Health Survey with complete data on household food insecurity (n = 8416). We used bivariate and multivariable logistic regression models to identify respondent- and household-level sociodemographic characteristics associated with household food insecurity. Results The prevalence of household food insecurity among adolescents was 20.7%. The adjusted odds of food insecurity were significantly elevated among adolescents who identified as Black or Indigenous (aOR 1.80), those living with a single parent (aOR 1.60), those living with a greater number of children ≤ 5 years (aOR 1.45) or 12–17 years (aOR 1.25), those in rented accommodation (aOR 1.98), those in households with only secondary school education (aOR 1.38), and those in households reliant on social assistance (aOR 2.03). Higher before-tax income was protective (aOR 0.99). In comparison with Ontario, the adjusted odds of food insecurity among adolescents were higher in Nunavut (aOR 6.77), Northwest Territories (aOR 2.11), and Alberta (aOR 1.48), and lower in Manitoba (aOR 0.66). Conclusion The markedly higher odds of exposure to household food insecurity among adolescents who are Black or Indigenous and those living in households characterized by markers of social and economic disadvantage highlight the need for more effective policy interventions to protect vulnerable families from this hardship.