Young children in communities facing socioeconomic disadvantage are increasingly targeted by school readiness interventions. Interventions are stronger if they address stakeholders’ priorities, yet children’s priorities for early school adjustment are rarely accounted for in intervention design including selection of outcome measures. The Children’s Thoughts about School Study (CTSS) examined young children’s accounts of their early school experiences, and their descriptions of what a new school starter would need to know. Mixed-method interviews were conducted with 42 kindergarten children in a socioeconomically deprived suburb of Dublin, Ireland. First, inductive thematic analysis identified 25 priorities across four domains: feeling able and enthusiastic for school; navigating friendships and victimisation; supportive environments with opportunities to play; bridging school and family life. Second, deductive analysis compared children’s priorities at item level against a school readiness outcome battery. Children’s priorities were assigned to three groups: (1) assessed by outcome measures (core academic competencies, aspects of self-regulation); (2) partially assessed (self-efficacy, social skills for friendship formation and avoiding victimisation, creative thinking, play); and (3) not assessed by outcome measures (school liking, school environment, family-school involvement). This analysis derived from children’s own perspectives suggests that readiness interventions aiming to support early school adjustment would benefit from considering factors children consider salient. It offers recommendations for advancing conceptual frameworks, improving assessment, and identifying new targets for supporting children and schools. In doing so we provide a platform for children’s priorities to be integrated into the policies and practices that shape their early lives.