Galectin-3 is a β-galactoside-binding lectin that plays a role in the regulation of several conditions that are associated with atherosclerosis. The goal of this cross-sectional study was to assess the association of plasma galectin-3 concentrations with sonographic measures of carotid atherosclerosis in the Atherosclerosis Risk in Communities study. Linear regression was used to determine the difference and 95% confidence intervals (CIs) for carotid intima–media thickness (cIMT) by categorical and continuous representations of galectin-3. Logistic regression was used to determine the odds ratio and 95% CI, separately, for dichotomized cIMT (75th percentile = 0.9 mm) and carotid plaque and/or shadowing. Compared to those in the first quintile of galectin-3, those in the fifth quintile of galectin-3 level had higher cIMT (mean difference: 0.020 mm after multivariable adjustment; P trend = .04). Moreover, compared to those in the lowest galectin-3 quintile, those in the highest galectin-3 quintile had higher odds of carotid plaque/and or shadowing (odds ratio 1.13 after multivariable adjustment; P trend = .014). Higher levels of galectin-3 are associated with greater carotid atherosclerosis. Our findings provide support for the role of inflammatory biomarkers in the pathogenesis of atherosclerosis and suggest galectin-3 as a possible target for intervention in the prevention or management of atherosclerotic disease.