Workforce readiness and preparation for post-secondary education in the 21st century are critical graduation outcomes for high school students to thrive in the emerging multicultural global society. Equitable access to college coursework in high school and support for course completion and attainment of college credit varies among school districts throughout New York State and often within high schools among its learners. Traditional high school structures and learning paradigms impact access to recruitment, enrollment, and support for academic attainment among diverse learners for participation and completion of college in the high school coursework. This study sought to determine how social justice leadership practices are used by district and school leaders to dismantle barriers to accessing college coursework in high school and create gateways to access for diverse learners to these advanced learning opportunities. A qualitative comparative case study was conducted to explore how district and school leaders use social justice leadership practices for the recruitment, enrollment, and academic support decisions for diverse learners for college in the high school coursework. The Social Justice Leadership Framework (Theoharis & Scanlan, 2021) was used as the theoretical framework. Two school districts in New York State that met established criteria were selected as cases. Seven participants were in each case, including district leaders, school leaders, school counselors, and teachers. The data set comprised 14 participant responses from 21 semi-structured interview questions and 26 district-related documents. Data was coded and categorized in NVivo 12 (QSR International, 2023) using the ten tenets of the Social Justice Leadership Framework (Theoharis & Scanlan, 2021), and emerging themes were identified. Findings for each case were determined. Cross-case analysis was conducted with the 40 individual case findings and specified 20 comparative findings, informing the discussion, conclusions, and recommendations. Several themes emerged. First, standard practices for communication and engagement strategies are frequently used with students and families. Next, data use in the recruitment and enrollment phases, if occurring at all, is limited, as well as data disaggregation to monitor student course completion and attainment of college credit. Also, policy, procedures, and fiscal resources impact a district's ability to provide college in the high school course opportunities, and enrollment decisions are affected using criteria and stakeholder roles. Additionally, partnerships with higher education, community-based organizations, and college readiness programs support access to enrollment opportunities for diverse learners. Lastly, diverse learners are more likely to complete courses and attain college credit when there is shared responsibility among adults for all learners through collaboration and professional learning. Findings indicate that district and school leaders' use of social justice leadership practices may foster increased access to college in the high school coursework among diverse learners and serve to guide authentic equity work among leaders. Recommendations for policy, practice, and future research concluded this study. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]