This paper draws on data collected as part of a study of the discourses of teacher professionalism amongst union active teachers in the Canadian provinces of Alberta and Ontario. Interviews revealed a triad of influences on the professionalism discourses of participants: engagement in teacher associations, the larger policy environment, and teacher agency. The manner in which this triad played out in each case, however, was unique to the particular political and organizational contexts framing the spaces in which such discourses were created. Using cross-case analysis, this paper specifically highlights the complex and contextualized nature of teachers' conceptions of professionalism, paying particular attention to the nuanced enabling and limiting conditions identified between the cases.