This study investigated the effectiveness of the Wordwall Application on students’ vocabulary mastery at SDN 50 Bengkalis. The objective of this study was to determine whether the use of the Wordwall Application had a significant effect on the vocabulary mastery of second-grade students. This research applied a quasi-experimental design using a non-equivalent control group design. The sample consisted of 44 students selected through cluster sampling, where class 2A served as the experimental class and class 2B as the control class. Data were collected through pre-tests and post-tests consisting of 20 objective vocabulary questions. The data were analyzed using descriptive statistics, validity and reliability tests, normality tests, homogeneity tests, paired sample t-tests, and independent sample t-tests with a significance level of 5% (α = 0.05). The findings showed that the mean score of the experimental class increased from 51.14 to 77.73, while the control class improved from 50.23 to 65.68. The paired sample t-test result showed a significance value of 0.000 < 0.05, indicating that H₀ was rejected and Ha was accepted. In addition, the independent sample t-test result showed a significance value of 0.004 < 0.05. Therefore, the Wordwall Application was proven effective on students’ vocabulary mastery.