Through a thorough review of research related to effective dispositional behaviors of educational leaders and with extensive input from subject matter experts, this research highlights twenty actionable behaviors associated with successful leadership in K-12 educational settings. The leadership dispositional behaviors identified in this study are indicative of promoting positive student outcomes, supporting the professional development of teachers, and creating positive work conditions for faculty and staff. The identification of leadership dispositions leading to performance-based growth and development in the discipline highlighted the need to address how postsecondary institutions can better prepare educational leadership candidates using sound measures. Adding to the body of educational leadership research, the Educational Leadership Disposition Assessment tool (EDLDA) was developed in this study using a systematic analysis of dispositional performance expectations in the discipline. The methodology for this research includes an extensive summary of steps taken to develop the EDLDA. Additionally, the psychometric evaluation of validated dispositional behaviors with calculated reliability estimates is presented in this research. Lastly, evidence of construct validity is also provided by aligning the validated dispositions with quality standards of the profession.