English vocabulary is one of the fundamental skills for young learners, yet Grade 1 students often face difficulties in memorizing and recalling new words due to limited attention span and passive learning methods. This study aims to determine the effectiveness of the Total Physical Response (TPR) method in improving the English vocabulary mastery of Grade 1 elementary school students. This research employed Classroom Action Research (CAR) design conducted in two cycles. Each cycle consisted of planning, action, observation, and reflection. The subjects were 25 Grade 1 students at [Nama SD] in Bandung. Data were collected through vocabulary tests, observation sheets of student engagement, and teacher field notes. The results showed that the application of TPR significantly improved students’ vocabulary mastery. In the pre-cycle, the average vocabulary test score was 58.4 with 32% of students achieving the minimum mastery criteria. After Cycle 1, the average score increased to 71.2 with 68% completeness. In Cycle 2, the average score reached 84.6 with 92% of students achieving mastery. Student engagement also increased from “passive” in the pre-cycle to “very active” in Cycle 2, as observed from their enthusiasm in following physical commands and responding to instructions in English. It can be concluded that Total Physical Response is an effective strategy for teaching English vocabulary to Grade 1 students. TPR makes learning more enjoyable, reduces students’ anxiety in speaking, and aligns with young learners’ kinesthetic learning style. It is recommended that teachers integrate TPR activities such as “Simon Says”, “Follow the Command”, and role-play games in daily English lessons.