Abundant research has shown that parents' parenting stress adversely affects their children's well-being. However, limited attention has been provided to parental bedtime involvement as a moderating mechanism linking parents' parenting stress to children's happiness. This study examined the moderating effect of parent bedtime soothing and parent-child bed-sharing on the relationship between parents' parenting stress and children's subjective happiness. Data were extracted from the Panel Study on Korean Children (PSKC). The study participants included 1,360 7-year-old first-graders from South Korea who experienced a transition from preschool to formal schooling. The results demonstrated (a) a negative effect of parents' parenting stress on children's happiness and (b) a moderating effect of parental bedtime soothing, which included maternal and paternal bedtime soothing, on the relationship between mothers' parenting stress and children's happiness. Conversely, parent-child bed-sharing did not moderate the relationship between mothers' parenting stress and children's happiness. In addition, neither parent bedtime soothing nor parentchild bed-sharing moderated the relationship between fathers' parenting stress and children's happiness. The findings of the study indicate that parental presence intended to soothe children at bedtime, as a family routine, buffers the adverse effect of mothers' parenting stress on their children's subjective happiness, regardless of the parents' gender. Our findings challenge the recommendations of parenting in Western cultures that children do not depend on a parental presence to fall asleep.