This study examined the association between maternal childhood food insecurity and their children’s stress, indexed by hair cortisol concentration. A total of 135 children (Mage = 45.66 months, SD = 10.71) and their parents participated in the study. Parents reported their experience of food insecurity during childhood, and their children’s hair samples were analyzed for hair cortisol concentration. Results demonstrated a significant positive correlation between maternal food insecurity during childhood and children’s hair cortisol levels, after controlling for children’s demographic variables and other aspects of economic hardship, including maternal childhood material deprivation and current education levels. This study discussed the long-lasting effect of early life food insecurity on stress across generations.