This study details the quantitative impact of educator leadership on student achievement outcomes for over 9,200 students in 398 fourth, fifth, and sixth grade classrooms within the Chula Vista Elementary School District, across 44 schools. Although the phenomenon of teacher leadership has been the subject of qualitative research for many decades, prior research has failed to establish a quantitative impact of educator leaders who serve as classroom teachers and serve in additional leadership roles. This study measured the student achievement outcomes of students in the classrooms of educators who were identified as leaders, as well as the classrooms of nonleader-identified educators. California Assessment of Student Performance and Progress (CAASPP) standardized assessment scores, which include the Smarter Balanced English/Language Arts and Mathematics scale score, were examined to determine student growth and performance from each group. The correlation of various factors on student achievement outcomes, including correlation of the presence or lack of educator leaders, were calculated and ranked. This study found that students in the classrooms of educator leaders serving as the classroom teacher achieved higher growth and performance with statistical significance in most cases. Additionally, this study determined that the correlation of educator leader status (presence or lack of and educator leader as the classroom teacher) is among the highest correlative factors with respect to English/Language Arts growth and is the highest correlative factor with respect to Mathematics growth. [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.]