Students With Disabilities (SWD) typically underperform compared to their non-disabled peers; these gaps are often widened by poverty, race or ethnicity, and English language proficiency. Principals are often unprepared to meet their learning needs. This mixed methods study took place in the Westford Central School District, a pseudonym, a high poverty (88.0%) district in New York State serving over 9,000 students who were 92.1% minority students, 42.5% English Language Learners, and 16.2% SWD. It explores the impact of 1) Principal Professional Learning Communities (PPLC) focused on increasing high-leverage leadership skills and 2) a data-driven principal-central office joint work to positively impact the learning climate and academic outcomes for SWD. The study used principal surveys, exit tickets, interviews, student and teacher school climate surveys, and STAR assessment data. The data showed that high-leverage leadership skills did not directly correlate to STAR assessment data or to student perceptions of climate. The data showed that high-leverage leadership skills correlated to teacher perceptions of climate by grade level band but not in aggregate. Principals gave themselves high scores for high-leverage leadership skills but nevertheless reported that the PPLC structure was very effective and valuable in increasing their leadership skills and knowledge about SWD. They also responded very positively to the joint work focusing on data conversations. Five themes emerged: 1) collaborative learning around best practices, 2) organization for learning, 3) participation in ongoing leadership networks, 4) learning leaders as reflective practitioners; and 5) data tailored central office professional support. [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 (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]