Teacher agency is essential for professional growth and teachers’ ability to support transformative student learning. This study looks into the potential of virtual reality (VR) as a joint practice teaching and reflective discussion environment for achieving language teacher agency. A group of teachers of an additional language (LX) participated in a telecollaborative project. They were provided with VR devices and language learning software, Immerse, for practice teaching and reflective discussions after each VR teaching. The data of this qualitative study were video recordings of the teaching and discussion sessions and the participants’ answers to an end-of-project questionnaire based on the Cognitive Affective Model of Immersive Learning (CAMIL) by Makransky and Petersen in 2021. The video recording analysis results showed that the participants used almost all the teaching facilitation functions (e.g., tools that allowed teachers to present content, conduct classroom management, and monitor students) provided by Immerse. The themes that emerged from the participants’ reflective discussions analysis also indicated mutual support for teacher agency development. Their responses to the questionnaire revealed that taking advantage of the teaching facilitation functions reflected the factors affecting learner agency as outlined in the CAMIL model. The findings of this study provided empirical evidence that VR environments can be a viable choice for teacher intercultural collaboration in which teachers of different backgrounds and experiences could together explore the potentiality of VR for teaching an additional language, sustain one another’s growth, and achieve teacher agency.