Effortful control, the ability to suppress a dominant response over a subdominant one, is a fundamental aspect of self-regulation. It has been observed that higher levels of parenting stress are associated with lower levels of effortful control in children. Perceived social support, an important factor in reducing parenting stress, may act as a buffer against the negative effects of parenting stress on children's effortful control skills. To investigate this assumption, we collected data from 199 mothers in Türkiye, who had children between the ages of 3 and 6 years. Mothers reported on their parenting stress levels, perceived social support, and their children's effortful control. Our results revealed that perceived social support moderated the relationship between parenting stress and children's effortful control after controlling for socioeconomic status. Moreover, the buffering effect of perceived social support became stronger as the level of social support increased, subsequently weakening the relationship between parenting stress and children's effortful control. These findings suggest that parental perceived social support plays a pivotal role in mitigating the adverse effects of parenting stress on healthy child development. These cross-sectional findings warrant a longitudinal investigation into the interrelations among parenting stress, perceived social support, and children's effortful control.