In the United States of America, each year almost one-third of all public high school students drop out before graduating and receiving a diploma. School librarians can play a critical role in strengthening and improving the academic achievement of all students, but especially those who are at-risk of dropping out of school. In this article, students most at-risk of dropout are identified. A research-based framework to improve student achievement through dispositions of the school librarian, nurturing relationships and supportive environments, and effective instructional practices is identified. Practical suggestions about specific school library programs are made. The article concludes with a section on implications for practice and suggestions for further study.