The association between family socioeconomic status (SES) and child executive functions is well-documented. However, few studies have examined the role of potential mediators and moderators. We studied the independent and interactive associations between family SES and single parenthood to predict child executive functions of inhibitory control, cognitive flexibility, and working memory and examined child expressive language abilities and family home environment as potential mediators of these associations. Sixty families from diverse SES backgrounds with a school-age target child (mean [SD] age = 9.9 [0.96] years) were evaluated. Child executive functioning was measured using a brief battery. The quality of the home environment was evaluated using the Home Observation for the Measurement of the Environment inventory. Family SES predicted the three child executive functions under study. Single parent and family SES were interactively associated with children's inhibitory control and cognitive flexibility; such that children from low SES families who were living with one parent performed less well on executive function tests than children from similarly low SES who were living with two parents. Parental responsivity, enrichment activities and family companionship mediated the association between family SES and child inhibitory control and working memory. This study demonstrates that family SES inequalities are associated with inequalities in home environments and with inequalities in child executive functions. The impact of these disparities as they unfold in the lives of typically developing children merits further investigation and understanding.