AbstractIntroductionLittle is known about the association between parents' and children's 24‐h movement behaviors during the pandemic. This cross‐sectional study examined the association between the 24‐h movement behaviors of parents and their preschoolers and investigated sex differences in this association.MethodsA total of 1740 preschoolers (4.5 ± 0.8 years old, 50.3% boys) and their parents (35.4 ± 4.9 years old, 24.3% males) in China participated in this study and provided valid and complete data. Parents completed an online survey or a written questionnaire in the period between October and December 2020. Preschoolers' and parents' movement behaviors (physical activity [PA], sedentary behavior [SB], screen time, and sleep) and demographic information were reported by the parents. Generalized linear models and logistic regression models were performed.ResultsPositive associations were found between parents' and preschoolers' moderate‐to‐vigorous intensity PA (β = 0.28; 95% confidence interval [CI]: 0.20, 0.36), total PA (β = 0.21; 95% CI: 0.17, 0.24), and sleep (β = 0.05; 95% CI: 0.03, 0.06) with no apparent sex difference. No significant association was found between parents' and preschoolers' SB or screen time. Girls were more likely to meet all three 24‐h movement guidelines when their parents met them (odds ratio = 2.38; 95% CI: 1.42, 4.01), but the relationship was not significant for boys.ConclusionsParental role‐modeling was positively associated with children's PA and sleep. This finding suggests that supporting parents' movement behaviors has the potential to promote a healthy lifestyle among preschoolers.