Objective: This study aims to examine the effects of early maternal postpartum depression on later child executive function. Method: The present study utilized data from the NICHD Study of Early Child Care and Youth Development and examined 589 participants. Measures assessed postnatal depressive symptoms (Center of Epidemiologic Studies Depression [CES-D]) and child executive functioning (Continuous Performance Task [CPT], Tower of Hanoi [TOH], Tower of London [TOL], and Stroop Test). Depression was measured at four points from 1 to 24 months and mothers were grouped into Depressed (at least one episode) and Non-depressed (no episodes) groups. Models included maternal education as a covariate. Results: MANCOVA revealed a significant main effect of maternal depression on child executive function (p = .014, partial η2 = .027). Significantly lower scores were observed on TOH Planning Efficiency at 1st grade (p = .002, partial η2 = .016, Depressed M = 13.683, 95% CI [12.839, 14.526], Non-depressed M = 15.429, 95% CI [14.728, 16.129]) and 5th grade (p = .014, partial η2 = .010, Depressed M = 22.985, 95% CI [22.074, 23.896], Non-depressed M = 24.486, 95% CI [23.729, 25.243]), along with TOL Perfect Solution Scores at age 15 (p = .021, partial η2 = .009, Depressed M = 52.089, 95% CI [50.395, 53.784], Non-depressed M = 54.705, 95% CI [53.298, 56.112]). No significant differences were observed for CPT Proportion of Incorrect Solutions or Stroop Interference. Conclusion(s): Results indicated that maternal depression was associated with poorer TOH and TOL scores in children when accounting for maternal education. Maternal depression was not associated with other measures of executive functioning including CPT and Stroop Test scores.