Sleep problems in preschool-aged children are common and predict further sleep difficulties and psychopathology. Negative parenting styles and parental psychopathology can shape young children’s sleep contexts and contribute to sleep problems. We examined longitudinal associations between parenting and mothers’ and fathers’ history of psychopathology and children’s sleep problems. Participants included 541 parents of children who were age 3 at the initial assessment and age 6 at follow-up. When children were age 3, parenting style was assessed using mother- and father-reported questionnaires, and maternal and paternal history of mood and anxiety disorders were assessed with diagnostic interviews. Preschoolers’ sleep problems at age 3 were associated with more sleep problems at age 6. Mothers’ history of anxiety disorders predicted increases in children’s sleep problems from ages 3 to 6. When mothers had a history of mood disorders, more authoritarian parenting at child age 3 was associated with fewer sleep problems at age 6. When mothers had a history of anxiety disorders, more permissive parenting at child age 3 was associated with more sleep problems at age 6. Finally, parental socioeconomic status was associated with increases in children’s sleep problems from ages 3 to 6. These findings suggest parents with a history of anxiety and mood disorders or from disadvantaged socioeconomic backgrounds may have children more vulnerable to experiencing sleep problems over time, particularly in the presence of less authoritarian and more permissive parenting. Interventions to support parenting practices and manage parental mood and anxiety may improve preschool-aged children’s sleep problems.