Food insecurity has been shown to be associated with fast-food consumption. However, to date, studies on this specific topic are scarce. Therefore, the aim of the present study was to investigate the association between food insecurity and fast-food consumption in adolescents aged 12-15 years from 68 countries (7 low-income, 27 lower middle-income, 20 upper middle-income, 14 high-income countries). Cross-sectional, school-based data from the Global School-based Student Health Survey were analyzed. Data on past 30-day food insecurity (hunger) and fast-food consumption in the past 7 days were collected. Multivariable logistic regression and meta-analysis were conducted to assess associations. Models were adjusted for age, sex, and body mass index. There were 180,164 adolescents aged 12-15 years [mean (SD) age 13.8 (1.0) years; 50.8% boys] included in the analysis. Overall, severe food insecurity (i.e., hungry because there was not enough food in home most of the time or always) was associated with 1.17 (95%CI=1.08-1.26) times higher odds for fast-food consumption. The estimates pooled by country-income levels were significant in low-income countries (adjusted odds ratio [aOR]=1.30; 95%CI=1.05-1.60), lower middle-income countries (aOR=1.15; 95%CI=1.02-1.29), and upper middle-income countries (aOR=1.26; 95%CI=1.07-1.49), but not in high-income countries (aOR=1.04; 95%CI=0.88-1.23). The mere co-occurrence of food insecurity and fast-food consumption is of public health importance. To tackle this issue, a strong governmental and societal approach is required to utilize effective methods as demonstrated in some high-income countries such as the implementation of food banks and the adoption of free school meals.