This qualitative study explores how school librarians perceive their role in promoting reading, and how they reflect on their professional identity. It also examines how the role of the school librarian is negotiated through power, legitimacy and collaboration with other professional roles within the school context. The study is based on six semi-structured interviews with practicing school librarians in Sweden. The collected data was analyzed using Lena Folkesson’s theoretical framework on three dimensions of collaboration; profession, power and legitimacy. The findings indicate that effective collaboration between school libraries and teachers/other professionals requires clear directives from school leaders regarding the school library’s mission, as well as establishment of mutual objectives and goals with other professional roles. Furthermore, the result highlights the school library as an essential cultural and literary resource, providing students with cultural experiences and access to literature they might not otherwise encounter. School librarians are identified as key actors in the development of children’s and adolescent’s reading skills.