This study examined whether maternal nutrition knowledge could help reduce the risk of obesity in children from food-insecure households compared to those from food-secure households. This cross-sectional study was performed on 327 mothers and their children. The children, aged 6-12 years, were recruited from primary schools throughout Shiraz, Iran. Food-insecurity and nutrition literacy were assessed using the Household Food-insecurity Access Scale (HFIAS) and a 60-item Food and Nutrition Literacy Assessment Tool (FNLAT), respectively. Logistic regression models were used to examine the association between children's overweight/obesity and maternal food and nutritional literacy (FNL) across food-secure households and those facing varying degrees of food-insecurity. One hundred thirty-three participants were classified as mild, 28 as moderate, and 7 as severely food-insecure. The results showed that maternal FNL was significantly associated with a reduced risk of overweight/obesity in children (odds ratio (OR) 0.29, 95% confidence intervals (CI) 0.17-0.51). Only moderate/severe food-insecurity was associated with overweight/obesity (OR 4.64, 95% CI 1.75-12.29). Both in food-secure and food-insecure households, good FNL was associated with a significant reduction in overweight/obesity risk compared to poor FNL. The findings suggest that nutrition education programs may be particularly beneficial for children living in food-insecure households, and that these programs should be tailored to address the specific needs of this population.