According to research, preschool physical environments (PPE) that promote outdoor play have a positive impact on children’s overall wellbeing, as well as their total developmental competence and academic learning, which then directly affects their school readiness prior to entering primary school. This study analyses the causative impacts of outdoor play on preschoolers’ school readiness for primary school in Klang Valley, Malaysia. Additionally, we attempted to extend a prior research conceptual model on outdoor play in studying the link between PPE and preschoolers’ school readiness. From June to August 2022, 84 private preschool operators from the Klang Valley took part in the survey to offer their viewpoints; however, only 72 completed questionnaires could be used for PLS-SEM analysis using SmartPLS 4. It has been discovered that outdoor play does, in fact, have a favorable, considerable impact on academic learning and school readiness. Other findings offer more proof of the causal links between outdoor play and children’s development. Important stakeholders, such as preschool providers, preschool designers, preschool educators, as well as parents, should make sure that appropriate outdoor play yards are provided in preschools for children’s full development and academic learning, as well as for preschoolers’ readiness for school.