Recent studies have assessed diet quality of low-income U.S. children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), but differences by race/ethnicity remain unknown. We assessed racial/ethnic disparities in nutrient intake from dietary sources (not supplements) among children participating in WIC, with a focus on priority nutrients and food groups for future WIC food package revisions, as described in a recent report by the National Academies of Sciences, Engineering, and Medicine (NASEM). We used data from the 2011–2014 National Health and Nutrition Examination Surveys (NHANES) and multivariable linear regression analysis to evaluate relationships between race/ethnicity and nutrient/food group intake of children participating in WIC. All data were analyzed using SAS 9.4 survey procedures, accounting for the complex survey design of the NHANES. Compared to non-Hispanic White children, Hispanic children had diets with better nutrient distribution and lower dietary energy density, while non-Hispanic Black children had diets with poorer nutrient intake. Hispanic children had higher potassium and fiber intake, and consumed more legumes, while non-Hispanic Black children had lower calcium and vitamin D intake, higher sodium intake, and lower total dairy intake, compared to non-Hispanic White children. These findings can inform WIC nutrition education messages and future food package revisions.