Virtual reality (VR) can be beneficial for learning and for increasing learners' engagement and motivation. However, aggregations of studies on language learning in high-immersion VR are scarce. This paper offers a systematic review of existing research on VR-based language learning, encompassing 32 peer-reviewed studies published between 2015 and 2020. The study yielded three main language-related findings: (1) multiple exposures to VR are necessary for effective learning; (2) VR is beneficial for contextual vocabulary learning; and (3) perceptions of language learning in VR are positive, but its effectiveness is inconclusive. We also describe VR technology trends, VR content used in language learning, and learners' perceptions of learning languages in VR. This systematic review is useful for language educators, researchers, and VR app developers.