Through the design of a survey and measure validation using exploratory factor analysis (EFA), we aimed to identify and define constructs required for special education teacher leadership that may inform the focus of professional development opportunities. Results of the analysis indicate a four-factor model is best suited for measuring special education teacher leadership capacity at the individual level. The teacher leadership domains that were defined through the EFA were as follows: (1) pedagogical confidence; (2) ethical considerations; (3) collaboration; and (4) assessment practices. Additionally, we identify differences between general and special education teacher identification of leadership skills, which can assist in targeting professional development to the specific needs of special education teachers that differ from general educators. Implications for research and professional development are presented to improve our understanding of and preparation of special teacher leadership. Through this work, we present a teacher leadership framework for the professional development of special education teacher leadership.