In 2020, 2.9 million households with children were food secure. Previous studies have demonstrated that reduced car access may contribute to issues of food security. This study examines whether using a personal vehicle by primary shoppers of households with children is associated with food security. Data were from US adults who were primary shoppers for households with children (N = 997) in the National Health and Nutrition Examination Survey 2017–2018. Participants reported their means of transportation to complete grocery shopping, which was categorized as using a personal vehicle or another mode of transportation. Household food security was measured using the US Food Security Survey Module and categorized as full food security, marginal food security, low food security, or very low food security. Multinomial logistic regression models estimated the association between transportation mode and food security. Adjusted models included age, race/ethnicity, education, and poverty-to-income ratio variables. 3.8% (SE: 0.6%) of US adults who are primary shoppers for households with children did not use a personal vehicle for grocery shopping. US adults who used a personal vehicle for grocery shopping were less likely to report very low food security [22.1% (SE: 7.4%) vs. 8.5% (SE: 1.3%), aOR = 0.4, 95% CI 0.1–1.0]. There were no differences in marginal food security [18.3% (SE: 3.3%) vs. 13.1% (SE: 1.7%), aOR = 0.9, 95% CI 0.6–1.5] or low food security [30.6% (SE: 8.7%) vs. 16.1% (SE: 1.7%), aOR = 0.6, 95% CI 0.2–1.7]. Future research and interventions should address how transportation access may contribute to food security in families with children.