Australia and the U.S. share many economic and cultural similarities, yet have policy differences in their support for children’s early education and care (EEC) which may have differential implications for children’s development. This study used nationally representative, longitudinal birth cohort studies from each country (LSAC-B and ECLS-B) to assess patterns of EEC among young children and implications of EEC for children’s cognitive skills following school entry. Results found that Australian children were more likely to use part-time EEC, and more likely to be in centre care during infant and toddler years than American children, whereas American children were more likely to use informal, home-based care and full-time EEC. Infant EEC was neither promotive nor detrimental for later cognitive skills. In both countries, later centre care was promotive of cognitive skills after school entry; these benefits came from toddler centre care in Australia and from preschool centre care in the U.S. Policy implications are discussed.