Data utilization is a key component of school improvement as data can be used to enhance student achievement both systematically and on an individual student level. Through systemically analyzing multiple sources of data, educators can make informed and knowledgeable school improvement decisions. In order to effectively make data-drive decisions that enhance student success, a promising strategy is the partnership, collaboration, and shared decision making between the school counselor and principal (Finkelstein, 2009). This relationship can help advance the effective utilization of data for school improvement, as both professionals utilize leadership skills in order to foster student growth and performance. In this article, the authors address aspects of the partnership principals and school counselors could form to develop the school's data utilization practices and thus enhance the capacity of teachers and other school personnel to improve the performance of students in the classroom and on standardized tests. The article begins with a discussion of the current interest in principal instructional leadership as a factor in school improvement. The authors then turn to the capabilities of school counselors and the roles they might play in collecting, analyzing, and interpreting student data as well as more effectively utilizing their knowledge and skills to work with teachers, other school personnel, students, parents, and community members. Next, they offer recommendations for creating a collaborative working relationship between principals and counselors to use data more effectively to improve classroom planning, instruction, and assessment; motivation and classroom management; and school climate and behavior management.