Background Suboptimal cardiovascular health (CVH) and social determinants of health (SDOH) have a significant impact on maternal morbidity and mortality. We aimed to evaluate the association of SDOH with suboptimal CVH among pregnant women in the United States. Methods and Results We examined cross‐sectional data of pregnant women aged 18 to 49 years from the National Health Interview Survey (2013–2017). We ascertained optimal and suboptimal CVH based on the presence of 0 to 1 and ≥2 risk factors (hypertension, diabetes, hyperlipidemia, current smoking, obesity, and insufficient physical activity), respectively. We calculated an aggregate SDOH score representing 38 variables from 6 domains (economic stability; neighborhood, physical environment, and social cohesion; community and social context; food; education; and healthcare system) and divided into quartiles. We used Poisson regression model to evaluate the association of SDOH with suboptimal CVH and risk factors. Our study included 1433 pregnant women (28.8±5.5 years, 13% non‐Hispanic Black). Overall, 38.4% (95% CI, 33.9–43.0) had suboptimal CVH versus 51.7% (95% CI, 47.0–56.3) among those in the fourth SDOH quartile. Risk ratios of suboptimal CVH, smoking, obesity, and insufficient physical activity were 2.05 (95% CI, 1.46–2.88), 8.37 (95% CI, 3.00–23.43), 1.54 (95% CI, 1.17–2.03), and 1.19 (95% CI, 1.01–1.42), respectively among those in the fourth SDOH quartile compared with the first quartile. Conclusions Over 50% of pregnant women with the highest SDOH burden had suboptimal CVH, highlighting the public health urgency for interventions in socially disadvantaged pregnant women with renewed strategies toward improving modifiable risk factors, especially smoking and insufficient physical activity.