BACKGROUND/OBJECTIVES: This study aimed to identify preschool children’s eating behaviors associated with early childhood obesity and its multi-level, socio-ecological determinants. SUBJECTS/METHODS: In a cross-sectional study of 364 mothers of preschool children aged 3–5 years, these children’s healthy eating behaviors were assessed using a validated preschool nutrition quotient (NQ-P) questionnaire. The children’s overweight or obesity statuses were determined based on body mass index percentiles from the 2017 Korean National Growth Chart. The associations between the NQ-P score and risk of overweight or obesity were examined using multivariable logistic regression. The associations of individual, maternal, physical, and media environmental factors with the NQ-P score were also examined using multivariable linear regression. RESULTS: Preschool children with greater NQ-P scores were at a significantly lower risk of overweight or obesity (P < 0.01). The NQ-P score had a significantly positive association with maternal body mass index and an inverse association with household income (all P < 0.05). Maternal parenting and feeding practices exhibited associations with the NQ-P score.Positive associations were observed with “warm,” “structured,” and “autonomy-supportive” parenting as well as monitoring feeding practices (all P < 0.05). In addition, the NQ-P score had a significantly positive association with the childcare center’s anti-obesogenic environment, such as the provision of nutritional and physical-activity support and vicinity of the built food environment to the home, including access to good-quality food, fruits and vegetables, and low-fat foods (all P < 0.05). Regarding media environments, the NQ-P score demonstrated more significant associations with viewing and eating and/or cooking content displayed on online video platforms (all P < 0.05) than with that on television. CONCLUSIONS Our findings confirm the significance of healthy eating behaviors in earlychildhood-obesity prevention and underscore the importance of multilevel maternal, physical, and media environmental interventions that effectively guide eating behaviors in preschool children.