Associations between stress, sleep, and functioning have been well-established in the general adult population, but not as well-established in the specific subpopulation of interest here-parents. To advance understanding of how maternal sleep is linked with both mothers' experiences of stress and their parenting, this study used actigraphic and mother-report measures of sleep, observed and mother reports of parenting, and measures of multiple stressors of relevance. In a community sample of mothers of toddlers (N = 314; child age M = 2.60, SD = 0.07 years), maternal stress was indexed with a cumulative risk score that combined sociodemographic risks and common parent stressors, including household chaos, role overload, parenting hassles, child misbehavior, negative life events, and lack of social support. We found that mothers who experienced shorter, later, and more variable sleep experienced higher levels of stress as indexed by the cumulative risk index. In addition, those with higher stress required longer to fall asleep and perceived more sleep problems. We also found that actigraphic measures of poor and insufficient maternal sleep were associated with less observed positive parenting, even when controlling for the cumulative risk index and maternal age, employment, and family size. Mothers who required longer to fall asleep also reported more dysfunctional parenting, with the same statistical controls. The findings, coupled with research showing that sleep is amenable to intervention, suggest that parental sleep may ultimately prove to be a useful intervention target for promoting positive parent involvement and responsiveness. (PsycINFO Database Record (c) 2019 APA, all rights reserved).