Background: Parents buy and prepare most food that grade school children eat, thus a parent's ability to inhibit their own impulses to buy less healthy foods may translate into what a child eats. Inhibitory control (IC) has been linked with diet in adults, but the impact of parent IC on child diet has not been explored. Methods: We examined 98 treatment-seeking parents (m age = 43.4; 89.2% with overweight/obesity (OW/OB); 85.4% female; 29.2% Hispanic) and their child with OW/OB (m age = 10.5; BMI%ile = 96.9%; 72.4% female; 29.2% Hispanic). Parent and child IC were measured using the Stop Signal Task (SST: average % of trials failed to inhibit). Child dietary intake information was collected in three 24-hour dietary recalls. Linear regression models examined associations between parent and child SST and child dietary intake (daily caloric intake, fat intake, glycemic load; Healthy Eating Index HEI total score and subscores for fruit and vegetables) adjusting for parent age and BMI, child age and BMIz, and family income. Results: Parent SST was positively associated with child dietary glycemic load (ß = 0.83, p < 0.01), such that better performance was associated with decreased intake of foods high in both glucose and carbohydrate. A positive relationship between parent SST and daily child caloric intake (ß = 6.6, p = 0.07) approached significance, as did a negative relationship between parent SST and HEI total score (ß = -0.15, p = 0.07). Analyses examining child SST on child dietary outcomes showed no relationship (p > 0.10). Conclusions: As hypothesized, poorer parent IC was associated with a less healthy child diet, but surprisingly, a child's own IC was not associated with their diet. This study suggests that a parent's inability to inhibit impulses to buy carbohydrate and sugar-rich foods directly affects their child's intake. Future studies should explore how factors such as parenting may mediate this relationship and utilize non-self-report measures of dietary intake.