To examine the reliability and validity of 1-mile walk tests for estimation of aerobic fitness (VO[subscript 2max]) in 10- to 13-year-old children and to cross-validate previously published equations. Participants (n = 61) walked 1-mile on two different days. Self-reported physical activity, demographic variables, and aerobic fitness were used in multiple regression analyses. Eight models were developed with various combinations of predictors. The recommended model for fitness testing in schools was: VO[subscript 2max] = 120.702 + (4.114 × Sex [F = 0, M = 1]) - (2.918 × 1-mile Walk Time [min]) - (2.841 × Age), R = 0.73, standard error of estimate = 6.36 mL·kg[superscript -1]·min[superscript -1]. Cross-validation of previously published equations demonstrated lower correlations with measured VO[subscript 2max] than the newly developed walk tests. Evidence of reliability and validity for 1-mile walk tests to estimate VO[subscript 2max] in young children was provided. The model that included 1-mile walk time, age, and sex may be appropriate for youth fitness testing in physical education, particularly for unmotivated or overweight young children.