This systematic literature review aims to offer an in-depth analysis of the existing research landscape regarding the application of the flipped classroom approach within the domain of language learning. The investigators methodically selected and analyzed 57 papers from 656 documents using a systematic and rigorous approach to literature selection. Our findings demonstrate the significant international impact of this field, with contributions from many countries and districts as well as globally excellent academic institutions. This review examines multiple areas of research, including improving students' perceptions and attitudes in flipped classrooms, language proficiency, motivational factors, etc. In addition, the research methods employed were evaluated, with a particular emphasis on mixed methods which combined the quantitative method with the qualitative method. Even though the application of flipped classrooms in language learning has achieved some achievements, some limitations are obvious. The most notable are the problem of sample size, the difficulty of technology integration, the lack of teacher training, the singularity of language research, etc. The research gaps revealed in this literature review, indicate interesting possibilities for future research. The diversity of research languages, the multiplicity of research methods, the integration of advanced technologies, and intensive teacher training will be significant of the area focus. This systematic literature review not only enriches the existing knowledge system but also has the potential to the direction of the development of flipped classrooms in language learning.