Introduction: Food security (FS) is defined as the existence of physical and economic access to sufficient, safe, and nutritious food to meet dietary needs. During the COVID-19 pandemic, all dimensions of FS were affected by the impact of health measures. Objective: To compare the level of food security in migrant and Chilean schoolchildren during the COVID-19 pandemic in the city of Antofagasta. Methodology: Cross-sectional analytical study. Recruitment was done through a non-probabilistic purposive sampling, 542 schoolchildren from first to eighth grade from the commune of Antofagasta participated. The ELCSA scale was used. The questionnaire battery was digitally designed. Descriptive analyses were performed through frequency distribution and the Chi-square test was used. Results: Total food insecurity at all levels in Chilean boys and girls was 74.3% and 71.2%, respectively. On the other hand, migrant children had total food insecurity levels of 73.6% and 75.9%, respectively. There were no significant differences between Chilean and migrant children. Conclusions: Reported levels of food insecurity are significantly higher in all categories than pre-pandemic levels regardless of nationality, sex, and educational level.