In this study, 85 maltreated foster children and 56 nonmaltreated community children (M age = 3–6 years) were assessed across kindergarten and first grade to examine the hypothesis that inhibitory control and caregiver involvement mediate associations between a history of maltreatment and foster placement and early school adjustment. Specifically, academic and social-emotional competence were evaluated. The maltreated foster children performed more poorly in academic and social-emotional competence. Inhibitory control fully mediated the association of maltreatment and foster placement with academic competence, whereas inhibitory control and caregiver involvement mediated their association with social-emotional competence. The results suggest that inhibitory control and caregiver involvement might be promising targets for school readiness interventions for foster preschoolers.