Children's play time has declined in recent decades, which could negatively impact early self-regulation-a vital component of school readiness. To date, studies have not fully explored how the time spent playing relates to children's self-regulatory skills, and in turn, their early reading and math competencies. Using data from time diaries and direct assessments of self-regulation, prereading, and math skills, this study examined how minutes spent playing at home predict these skills in a sample of 128 children followed from age four to five. Additionally, it considered whether self-regulation explained links between play time and prereading and math. Results showed that the time spent playing positively related to children's self-regulation. Moreover, through its association with self-regulation, play time had indirect effects on prereading and math skills measured one year later. Results suggest that fostering opportunities for play time during the preschool years may help to boost school readiness skills.