Objective: To evaluate demographic differences in parent website engagement in a child care−based wellness intervention. Design: Parent-reported demographic characteristics and observed website engagement were averaged by child care centers participating in the web-based intervention arm of a cluster randomized controlled trial of wellness interventions. Setting and Participants: Parents of preschoolers in 17 Maryland child care centers. Main Outcome Measures: Website engagement: (1) webpage views, (2) average time on webpage, and (3) intervention activity completion. Intervention: Parents received access to a website containing content on wellness-promoting topics (eg, parenting, nutrition, physical activity) and their child care center’s activities. Analysis: Cross-sectional differences in website engagement by demographic characteristics were assessed using ANOVA. Results: Centers with a high proportion of parents who identified as other than non-Hispanic White and had less than a bachelor’s degree had significantly fewer webpage views, and completed significantly fewer intervention activities compared with centers with parents who were predominantly non-Hispanic White and had more than a bachelor’s degree. Conclusions and Implications: Demographic differences in parents’ child care center website engagement represent disparities that could contribute to health inequities in parents’ access to wellness-promoting material. Future efforts could identify factors that eliminate demographic disparities in parent engagement in web-based interventions. (author abstract)