This qualitative multiple case study considered language teacher identity and what it means to “be authentic” as a teacher of French. It investigated the identity construction of 87 French as a second language (FSL) teachers from British Columbia who participated in a two-week professional development sojourn to France in 2009. The study examined how participants described their experiences abroad in relation to their teaching practices in Canada, and how these accounts made evident particular understandings of cultural and linguistic authenticity. The analysis focused on the way participants’ narratives served to authenticate (Bucholtz, 2003) L2 teacher identity and how conceptions of authentic language and L2 learning and teaching represented both constraining and productive ways of “being” a certain kind of FSL teacher. Broadly situated within a practice theory framework, FSL teacher identity was first considered through a wide-scale analysis of data from the larger cohort of BC teachers, followed by a micro-analytic examination of individual processes of identification “performed” by seven focal participants. The analyses highlighted the extent to which the “FSL teacher” category, grounded in a “native speaker” ideology, ultimately informed the identity constructions of each individual teacher. The various identity positionings manifested by focal participants shed light on a complex of language ideologies relevant in discourses operating within the FSL profession in Canada with implications for what it means to be practicing as “non-native speaker teacher” in this context. Given current empirical emphasis on the sociolinguistic and cultural aspects of language learning and teaching (Firth & Wagner, 1997; Lafford, 2007), the present study answers a recent call in applied linguistics for a more rigorous analysis of identity which moves away from the idea of identity as a simple collection of essentialist categories (Dervin & Kramsch, 2011). It does so by foregrounding a discursive-constructionist orientation and attending to the interactional nature of identity construction, along with a thoroughgoing consideration of researcher reflexivity. The study makes significant contributions to applied linguistics research in the areas of study abroad, L2 teacher development and identity, and the workings of prevalent ideologies informing L2 language teaching and research.