In several studies, collaborative action research has been shown to be a productive approach to enabling teachers to incorporate critical thinking into their pedagogy; however it has not been investigated in the Indonesian context. To address this gap, we facilitated a collaborative action research project with a small group of English language teachers in Indonesia. We organised three online focus group discussions (FGDs), shared resources, and mentored the teachers via phone and WhatsApp. The case study confirms that collaborative action research involving practising teachers and academic mentors in Indonesia has the potential to bring about transformation: to different degrees, the teachers took on new identities and expanded their repertoire of teaching strategies for critical thinking.