Engagement in peer play is an important factor in young children’s adjustment as they make the transition to school. We evaluated individual differences in peer play within a sample of 58 children aged 4–5 years. Among boys, but not among girls, emotion understanding and verbal ability independently served as positive predictors of interactive peer play and negative predictors of disconnected play. Among girls, but not among boys, interactive peer play and socio-moral reasoning about peer conflict situations independently predicted sociometric most-like nominations. The results provide a foundation for further research on divergence in the early peer play of girls and boys.