Lisa A.D. Kobandaha. 321418076. 2023. Utilizing Busuu Application to Facilitate English Vocabulary Learning Among Primary School Students in Bolaang Mongondow, A Case Study. Skripsi. English Language Education Study Program, Faculty of Letters and Cultures, States University of Gorontalo. Principal Advisors Prof. Karmila Machmud, S.Pd, M.A., Ph.D and Sri Widyarti Ali, S.Pd., M.Hum. Technology is a media that makes it easier for students to search for information or learn something through the mobile apps found on each smartphone. This study aims to determine whether the use of the Busuu application can improve children's vocabulary mastery. The research design used the Pre Experiment method. This study took 20 fourth-grade students of SD Cokroaminoto Solog as a sample. The data collection technique is that researcher collect data with several procedures consisting of pre-test, treatment, and post-test. The results of this study indicate that the average pre-test score is 50.08 and the post-test average score is 75.6. In addition, the results of the research hypothesis found that Sig. (2-tailed) < 0.05 or 0.00 < 0.05. It means the research hypothesis is accepted. Therefore, using the Busuu application can improve the vocabulary mastery of children/students. Keywords: Busuu Application, Vocabulary, Teaching and Learning English