Background: We used a multi-method and multi-informant design to identify developmental pathways through which parental depressive symptoms contribute to children's sleep problems. Environmental factors including adult inter-partner conflict and parent-child conflict were considered as process variables of this relation. Methods: An ethnically and socioeconomically diverse sample of children (n = 268) participated (M age = 9.44 years, SD = 8.61 months). Children wore actigraphs for 7 consecutive nights and also reported on their sleep problems. Results: Higher levels of maternal depressive symptoms were associated with children's sleep/wake problems. Higher levels of paternal depressive symptoms were associated with shorter time in bed and fewer sleep minutes. Inter-partner conflict and parent-child conflict were mechanisms of effects in the associations between maternal depressive symptoms and children's actigraphy-based and self-reported sleep problems. Conclusions: Findings build on this scant literature and highlight the importance of identifying pathways of risk and familial and environmental influences on children's sleep problems.