ABSTRACT This study aims to determine the effectiveness of Wordwall learning media on English vocabulary mastery of grade III students of MI Ma'arif NU Beji Kedungbanteng, Banyumas. This study used a quasi-experimental design with a pretest-posttest control group model. Two classes were selected randomly: one as an experimental group using Wordwall media and another as a control group not using Wordwall media. The test instrument consisted of 25 multiple-choice questions designed to measure students' vocabulary mastery. Data were collected through pretest and posttest, then analyzed using statistical techniques, including validity, reliability, N-Gain, and t-test. The findings showed a statistically significant improvement in vocabulary scores for the experimental group. The paired t-test revealed a p-value of 0.000 < 0.05, indicating a significant difference before and after the intervention. Additionally, the N-Gain analysis categorized the learning improvement in the experimental group as "high" with a gain score of 0.74, which falls into the "effective" category. These findings conclude that Wordwall media can improve students' vocabulary mastery and make English learning more interesting and effective for elementary school children. Keywords: English learning, learning media, vocabulary mastery, wordwall