In 2022, National Literacy Trust discovered that 1 in 7 state primary schools in the UK lacked a dedicated library or reading space. This figure rises to 1 in 4 schools in the most disadvantaged communities (PSLA, 2022). Yet, it is known that school libraries are vitally important: they not only provide children with access to books at a time when household finances continue to be tight due to the cost-of-living crisis, but they also help to promote reading for pleasure at a time when reading-for-pleasure rates among children are plummeting. The Libraries for Primaries campaign is a group of organisations that work to address the lack of investment in primary school libraries. The campaign mission is to ensure that every primary school in the UK has the resources, training and books they need to sustain an engaging up-to-date library at the heart of their school. In the 2023-24 academic year, they worked with 450 primary schools across seven programmes. Overall, this evaluation showcases the impact of investment in the transformation and promotion of school libraries and highlights the importance of school libraries in fostering reading at the individual and the school level, both immediately and over time.