Résumé : This study aimed to estimate disparities in dietary habits according to the individual and contextual socioeconomic status (SES), while taking into account school nutrition-related characteristics. Data came from the 2018 cross-sectional "Health Behaviour in School-aged Children" (HBSC) survey. Multilevel multiple logistic regressions were performed. Over two-thirds of the observed variance was explained by individual and school characteristics, with SES being the main contributors. For example, 76.9% of the variance in daily sugar-sweetened beverage (SSB) intake was explained by individual and school characteristics. Adolescents of a secondary or lower parental education level were more likely to consume SSB daily than those of a post-secondary level (aOR = 1.46 (1.29-1.66)). Compared to those in a high SES school, the odds to consume SSB daily was higher for adolescents in low SES schools (aOR = 2.37(1.90-2.96)). These findings support the need for schools to pursue a consistent nutrition policy, with an increased support in low socioeconomic populations.