OBJECTIVES:This study explored the association between dietary and suicidal behaviors of Korean adolescents and investigated differences in this association in children of immigrant parents.METHODS: The sample (n=368,138) was collected from the Korea Youth Risk Behavior Survey from 2015 to 2020. Participants who agreed to provide family information (n=313,689) were classified according to their parents’ nationality. The study variables were 11 self-reported dietary behaviors, and their composite dietary behaviors (i.e., nutrient deprivation and unhealthy food consumption) that resulted from principal component analysis. The association between study variables and suicide-related outcomes (i.e., suicidal ideation, suicide planning, and suicide attempts) was analyzed by multiple logistic regression with adjustment for covariates. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated.RESULTS: Participants who skipped key meals and foods were more likely to have attemped suicide (aOR [95% CI]: skipping breakfast ≥5 days/wk, 1.28 [1.21 to 1.35]; consuming fruits <1 times/wk: 1.42 [1.32 to 1.52]; consuming vegetables <1 times/wk: 1.72 [1.53 to 1.93]; consuming milk <3 times/wk: 1.07 [0.99 to 1.16]). The associations were prominent in third culture kids (TCKs) (aOR [95% CI]: 2.23 [1.61 to 3.09]; 2.32 [1.61 to 3.35]; 2.63 [1.50 to 4.60]; 1.69 [1.09 to 2.63], respectively). Participants who consumed unhealthy foods (fast food, caffeinated and sugary drinks) more frequently were more likely to have attempted suicide (aOR, 1.55; 95% CI, 1.38 to 1.73). This association was also more prominent in TCKs (aOR, 2.08; 95% CI, 1.08 to 4.01).CONCLUSIONS: Our findings indicate a positive association between unfavorable dietary behaviors and outcomes related to suicide, and this association appears to be notable in adolescents with immigrant parents.