<p>This study investigates the association between sleep duration and attentional and behavioral outcomes in preschool children of mothers with depression, a group at elevated developmental risk. Exploring data from the Future of Families and Child Wellbeing Study (<i>N</i> = 2945; female = 48%), we examine whether longer sleep durations are associated with reduced attentional and behavioral issues in these preschoolers from low-income, high-risk families. Specifically, we focus on attentional, externalizing, and internalizing problems. Our analysis employs both linear and non-linear models to parse the intricacies of sleep’s role on child behavior. Findings suggest that adequate sleep may play a key role in mitigating the negative developmental impacts of maternal depression. These insights pave the way for targeted interventions that could bolster child development through improved sleep practices.</p>