The professional identity of language teachers has gained prominence in research on language instruction in the last decade. This article adds to work by critically exploring how teacher education programs allow non-native English-speaking teachers (NNESTs) to construct positive professional identities and become pro-active educators. It reports on a study of the discursive constructions of professional identities that 20 NNES pre-service teachers developed within a Master of Education TESOL program for international students in a Canadian university. Drawing on post-structural and sociocultural understandings of identity, the article offers a Bakhtinian analysis of the negotiations and dialogical appropriations of authoritative program discourses that these pre-service NNESTs reflected upon in portfolios summarizing their learning in the program. The article concludes by describing the implications of this research for TESOL and cost-recovery international programs in British, Australian, and North American universities.