Purpose: The purpose of this mixed methods study was to define the roles of school librarians as perceived by librarians and principals in regard to the ALA/AASL Standards for the Initial Preparation of School Librarians (2010). This study was designed to explore the perceptions of librarians and principals on the role of the librarian in the school and library. The views of librarians and principals were explored on how the library enhances student achievement. Method: A mixed methods approach was used to learn the perceptions of the librarians and principals on the role of the librarian. The study was conducted in a school district in Texas. All of the principals and librarians in the district were invited to participate. The survey was sent to 57 librarians and 23 principals. The data was collected using a survey that was administered through the online tool SurveyMonkey. The survey consisted of twenty-one questions that were a combination of Likert scale and open-ended questions. Findings: The librarians rated their library programs as good, but with room for improvement under the standards. When the librarians were asked to define their roles in their own words, they defined themselves as librarians, teachers, leaders, and managers. When asked how they believed that their principals view the role of the librarian, many thought that they were viewed as clerks and support staff. Some of the librarians stated that their principals saw them as teachers and literacy leaders. The librarians felt that their library programs enhance student achievement, but that more support would allow them to enhance student learning even more. The principals rated their library programs and librarians as excellent under the standards. When asked to define the role of the librarian in their own words, the principals called them literacy advocates, cheerleaders, team players. When the principals were asked to define the role of the librarian in the school, they stated teacher, leader, and literacy advocate. The principals felt that the library enhanced student achievement, and the librarians support student learning by encouraging reading as well as teaching skills that reinforce what is learned in the classroom. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]