The Supporting Behaviour in the Early Years project is a longitudinal study tracking children’s (n = 240, 101 male, 139 female) development, school liking, language, learning, relationships and behaviour through the early years of school. In this paper, we examine emergent gender differences in (i) children’s language, development, academic achievement, relationships and behaviour; (ii) teacher concerns, and (iii) the provision of support in the first two years of school in Queensland: Prep and Grade 1. In the first year of the study (prep), significant differences were found in relation to teacher-rated relationship quality and child behaviour, and teacher concerns. Yet, there were no differences in children’s early learning, child-rated teacher attachment, attitudes to school, or the amount and types of support children received. Further differences emerged in the second year of the study, when the participating children were in Grade 1. Findings suggest greater focus on building positive student-teacher relationships, mitigating teacher expectancy effects, and improving learning support identification/provision processes in the early years of school could be of significant benefit to children from disadvantaged backgrounds.