ObjectiveChildhood obesity is a public health concern that often worsens with age. Although several risk factors at the child and maternal levels have been identified in cross‐sectional studies, less is known about their long‐term contribution to racial/ethnic disparities in childhood obesity. This study examines child‐ and maternal‐level factors associated with the growth trajectories of White, Black, and Latino children.MethodsGroup‐based trajectory models were used to identify BMI z score trajectories from birth to 9 years of age among White, Black, and Latino children. The associations of child‐ and maternal‐level factors with the trajectory group identified as at risk for obesity were examined using adjusted logistic regression analysis, stratified by race/ethnicity.ResultsAmong White children, fast‐food consumption (odds ratio [OR] = 1.66; 95% CI: 1.09‐2.52) was associated with higher odds of following an at‐risk trajectory. Among Black and Latino children, prepregnancy BMI was associated with following an at‐risk trajectory (OR = 1.05; 95% CI: 1.03‐1.08 for Black children, and OR = 1.12; 95% CI: 1.07‐1.17 for Latino children).ConclusionsThese findings showed racial/ethnic differences in the risk factors that influence the likelihood of obesity during childhood. Further research is needed to identify modifiable racial/ethnic specific risk factors to guide obesity‐prevention interventions.