Racial and ethnic disparities and language barriers coexist with inequities in a child’s educational, environmental, and economic opportunity. We evaluated the association between surgical outcomes and a composite child neighborhood opportunity index (COI), race and ethnicity, and language barriers among children undergoing congenital heart surgery. Utilizing the Society of Thoracic Surgeons database, we conducted a single-center retrospective cohort study of patients who underwent congenital cardiac surgery from 2010 to 2023. Patients were classified by quintile COI scores based on their reported address. Outcomes included in-hospital mortality, length of stay (LOS), and major complications. Adjusted analyses were performed using generalized linear mixed models. Among 1,568 patients, 51.2% were non-Hispanic White and 64.1% had public insurance. 57.4% lived in very low or low COI neighborhoods. Race, ethnicity, primary caregiver language, and insurance payer were significantly associated with COI (p < 0.0001). After adjustment, COI was not associated with mortality, LOS, or complications. Compared with non-Hispanic White patients, non-Hispanic Black patients had higher odds of in-hospital mortality (OR 2.19, 95% CI 1.07–5.30) and longer LOS (β = 0.25, 95% CI 0.09–0.42). Patients with non-English-speaking caregivers had longer LOS (β = 0.30, 95% CI 0.10–0.51). Neighborhood opportunity was not independently associated with surgical outcomes. However, disparities by race and ethnicity and language persisted, suggesting that COI may not fully capture structural racism or communication barriers in pediatric cardiac care.