Speaking skills had always been the most challenging skill among the pupils in language learning. The flipped learning approach is an innovative teaching and learning pedagogy that creates better learning experiences in order to improve pupils' speaking skills. Therefore, this systematic literature review focuses on flipped learning approach in improving pupils' speaking skills. This analysis is done based on the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) review methodology. A total of 39 articles related to flipped learning in improving speaking skills published between 2017 to 2020 were identified from Scopus, Google Scholar and ERIC databases. Based on the results, self-regulated learning, interaction, motivation and achievement were the key themes that promotes the benefit of flipped learning to improve pupils' speaking skills. Hence, this paper is beneficial to policy makers, educators and students in utilizing flipped learning approach to improve pupils' speaking skills from various levels of education.