"The Perceptions of Elementary Principals Regarding Their Role in Building Teacher Capacity" is a sequential explanatory mixed methods study and includes quantitative and qualitative elements. In public schools throughout the Commonwealth of Massachusetts, the responsibility for building increased teacher capacity falls primarily on elementary school principals. This study collected the experiences and behaviors of elementary principals in Massachusetts to gain insight into their understanding of their role in building teacher capacity. This study was guided by three research questions: 1. To what extent do elementary principals consider the capacity of teachers to be a principal leadership priority? 2. In what ways do elementary principals report they build teacher capacity? 3. What are the factors and conditions that occur within the school day that elementary principals identify as supporting or inhibiting their efforts to increase teacher capacity? This study collected data from 79 elementary principals through a questionnaire, with nine of those school principals providing qualitative data in the form of follow-up interviews. The study's seven findings identified the elementary principal's primary role in building teacher capacity; and the strategies and practices that are effective in supporting this. Recommendations offer effective strategies and approaches principals can use to increase teacher capacity taking cognizance of the importance of culture and climate as an influencing factor. [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.]