This study examined the relationships between stress, depression, body mass index, and food addiction in South Korean nursing students. Data from 323 nursing students in Seoul, Gangwon-do, Jeollanam-do, Gyeongsangnam-do, and Jeju-do were collected via self-report questionnaires and analyzed using chi-square tests, Mann–Whitney U tests, logistic regression analyses, and the receiver operating characteristic curve using SPSS 21.0. Overall, 7.1% of students were classified as having a food addiction. Stress and depression affected food addiction, and food addiction influenced obesity. Depression and stress combined were predictors of food addiction. These findings suggest that effective stress management and interventions for depression prevention may be beneficial to prevent food addiction in nursing students.