In 2018, the Great School Libraries Campaign was launched with the aim of bringing school libraries and librarians to every school in the UK, and to gather data on the quality and quantity of school libraries that already exist. Previous research has clearly highlighted the importance of school libraries, not just for children and young people's reading and writing skills but also for their general academic attainment and wider learning skills. This includes their motivation and attitudes towards reading and other personal and interpersonal outcomes such as self-esteem and feelings of success. In this report, the authors discuss school libraries from the point of view of children and young people. Using data from 45,523 children and young people who took part in their Annual Literacy Survey from November 2017 to January 2018, it explores how many children use the school library, why they do or do not use it, how school library use links with literacy engagement and reading skill, and how it relates to mental wellbeing.