There is a need to better understand the influence of daytime parenting behaviors on children’s sleep. We investigated relations between maternal harsh parenting and young children’s sleep and consistent with health disparities and cumulative risk perspectives, socioeconomic status was considered as a moderator of these associations. Participants were 172 mothers of children between the ages of 2 and 5 years (mean age of children was 3.30 years) from diverse ethnic (47% of children were White/European American, 24% were Hispanic/Latino, 29% reported other ethnicities) and socioeconomic backgrounds. Mothers reported on children’s sleep/wake problems (insufficient sleep duration, night wakings, daytime sleepiness) and their own harsh parenting behaviors. After controlling for several covariates, more maternal harsh parenting was related to greater daytime sleepiness among children. Associations between maternal harsh parenting and insufficient sleep duration and night wakings were significant for children from lower socioeconomic backgrounds. Results add to the growing literature that has considered children’s sleep in the family context and highlight the importance of contemporaneous considerations of the parenting and socioeconomic contexts.