Despite identified concurrent socioeconomic disparities in children’s sleep, little research has examined pathways explaining such associations. This study examined the quality of the home environment as a direct predictor of sleep and potential mediator of associations between early life socioeconomic status and objective and subjective indicators of sleep in middle childhood. A socioeconomically and ethnically diverse sample of 381 twin children (50% female; 46.6% lower middle class or living at or below the poverty line; 26% Hispanic/Latino) were assessed at 12 months for SES and eight years using gold-standard home environment interviews and actigraphy-measured sleep. Multilevel mediation path models indicated that lower early SES and lower quality concurrent home environments were associated with shorter sleep durations, longer sleep latencies, and greater sleep timing variability. The home environment significantly mediated associations with sleep duration and sleep timing variability. The findings illustrate an important target in the prevention of poor childhood and adolescent sleep.