Obesity remains a public health issue, especially for Blacks (or African Americans). Obesity is thought to reflect a complex interaction of socioenvironmental, biological, and cognitive factors. Yet, insufficient attention has been given to psychosocial factors like social cohesion within the African American community. Using multivariable linear regression, we examined the association between social cohesion, measured by the Social Cohesion and Trust scale, and body mass index (BMI) with cross-sectional data (n = 1467) from a cohort study (2008–2009). Greater social cohesion was associated with lower BMI (b = -0.88; 95% CI: −1.45, −0.32) in an unadjusted model. The association was strengthened after further adjusting for relevant covariates (i.e., individual-level sociodemographic factors, health behaviors, and depressive symptoms) (b = -1.26; 95% CI: −1.94, −0.58). Future research should examine potential mechanisms underlying the association between social cohesion and BMI with longitudinal data. In the meantime, obesity prevention and intervention measures should consider promoting social ties and bonds to lower BMI in African American communities.