Teacher effectiveness has long been identified as critical to student success and, more recently, supporting students attaining the skills and dispositions required to be successful in the early 21st century. To do so requires that teachers engage in professional learning characterized as a shift away from conventional models of evaluation and judgment. Accordingly, school and system leaders must create “policies and environments designed to actively support teacher professional growth” (Bakkenes, Vermunt, & Webbels, 2010). This paper reports on the Alberta Teacher Growth, Supervision, and Evaluation (TGSE) Policy (Government of Alberta, 1998) through the eyes of teachers, school leaders, and superintendents. The study sought to answer the following two questions: (1) To what extent, and in what ways, do teachers, principals, and superintendents perceive that ongoing supervision by the principal provides teachers with the guidance and support they need to be successful? and, (2) To what degree, and in what ways, does the TGSE policy provide a foundation to inform future effective policy and implementation of teacher growth, supervision, and evaluation? Results affirm international findings that although a majority of principals consider themselves as instructional leaders, only about one third actually act accordingly (OECD, 2016).