In this study we used data on a sample of children in the Chicago Public Schools in areas of concentrated poverty-related disadvantage to examine associations between school climate and low-income children’s language/literacy and math skills during the transition to kindergarten. We also explored whether teacher-child closeness moderated these associations. Multilevel modeling analyses conducted using a sample of 242 children nested in 102 elementary schools revealed that low adult support in the school was significantly associated with children’s poorer language/literacy and math skills in kindergarten. Teacher-child closeness predicted children’s higher language/literacy and math scores and moderated the association between low adult support and children’s academic skills. Among children who were high on closeness with their teacher, those in schools with high levels of adult support showed stronger language/literacy and math skills. There were no significant associations between adult support and the academic skills of children with medium or low levels of teacher-child closeness. Results shed light on the importance of adult support at both school and classroom levels in promoting low-income children’s academic skills during the transition to kindergarten.