This study utilized critical leadership praxis (CLP) (Pak & Ravitch, 2021) framework in an intrinsic case study of Institutional Effectiveness/Institutional Research (I.E./I.R.) leaders within the California State University (CSU) system to explore how data-informed decision-making processes incorporate the understanding of varying interrelationship student identities and communities to enhance diversity, equity, inclusion, and justice (DEIJ). Recognizing the complexity of student identities, which encompass not just racial, gender, and socio-economic elements but also first-generation status and other personal characteristics, this research seeks to understand how I.E./I.R. leaders interpret and engage with these varying interrelationships of student identities and communities to promote equitable educational outcomes. The findings reveal that I.E./I.R. leaders are shifting from the traditional roles of data custodians to initiative-taking strategists, utilizing complex data to inform and drive DEIJ initiatives across their campuses. This study highlights the leaders' personal commitments to DEIJ, reflecting in their advocacy for nuanced data practices and strategic leadership that challenge systemic inequities and foster a culture of inclusion. The transformation of data management practices and the enhancement of data literacy among stakeholders is essential for advancing DEIJ within the CSU system. Moreover, the research discussed the necessity of continuous professional development and the integration of advanced technologies to support effective data use, ensuring that DEIJ efforts are sustained but more importantly continuously improved. This intrinsic case study not only underscores the critical role of I.E./I.R. leaders in shaping a more equitable educational environment but also provides insights into the ongoing challenges and opportunities for fostering genuine institutional change towards equity and inclusion for all students within the CSU system. [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.]