Internationalization increasingly shapes the work of English language teachers in Brazil’s Federal Network of Vocational, Scientific, and Technological Education, yet professional development often positions them as implementers of externally designed agendas. This article examines how three English language teachers collaboratively constructed meanings of teacher (trans)formation during a five-month online course on the internationalization of education. Grounded in Critical Applied Linguistics and critical-collaborative action research, the study draws on six collective reflective sessions held in 2022. The recordings were transcribed and analyzed through an iterative thematic process that attended to explicit statements, tensions, and silences. Six meaning domains were identified and reorganized into three interdependent movements: epistemic-pedagogical reorientation, which brought together the re-signification of classroom practice and the strengthening of teacher-researcher identity; relational-institutional reorientation, which involved peer collaboration and the recognition of systematic professional learning as an institutional need; and linguistic-political reorientation, which encompassed the decentering of English and the strengthening of teacher agency in internationalization. The findings show that participants constructed (trans)formation less as the acquisition of techniques than as a relational, unfinished process of questioning established practices, identities, language hierarchies, and institutional arrangements. Because the evidence is discursive and the action-research cycle was only partially implemented, the article does not claim to demonstrate sustained behavioral change. It argues that critical internationalization requires formally allocated time within teachers’ workloads, institutional support, a multilingual orientation, and teachers’ participation as knowledge producers and policy actors.