Ascertaining the value of a study abroad experience on facilitating language development has long been a goal of Second Language Acquisition scholars. There is currently a plethora of studies regarding the topic, yet, despite this, the evidence remains inconclusive and contradictory. This systematic review evaluates the impact of study abroad among undergraduate language learners in both Europe and beyond on a range of linguistic outcomes compared to remaining in domestic instruction. Studies that used a randomised controlled trial design, or a quasi-experimental design which achieved baseline equivalence, were included in an in-depth review as they offer the best available evidence on impact. Nine electronic databases were searched using a series of keywords. Articles were screened using pre-specified inclusion criteria. Forty studies were identified for a mapping synthesis, with seven publications being carried forward to full data extraction and quality appraisal. The synthesis of the evidence indicated that sojourning can facilitate the development of global proficiency and oral fluency, while oral and written accuracy demonstrated less change. The available evidence is discussed in relation to policy and practice, together with the limitations of this review.