Background of study: Fundamental Movement Skills (FMS) are essential for children's physical development and long-term participation in physical activity. However, increasing sedentary behavior among children has contributed to a decline in motor competence worldwide. Aims and scope of paper: This study aimed to examine the effectiveness of the traditional Indonesian game Engklek in improving locomotor skills among elementary school students. Methods: A quasi-experimental design with a non-equivalent control group pretest–posttest was employed involving 26 third-grade students (14 boys and 12 girls) from MI Al Hikmah Sendang, Indonesia. The experimental group (n = 13) participated in an Engklek-based intervention program consisting of eight sessions conducted over four weeks, while the control group (n = 13) followed the regular physical education curriculum. Locomotor skills were assessed using the Test of Gross Motor Development-2 (TGMD-2). Results: The results showed a significant improvement in the experimental group’s mean score from 70.40 to 87.29 (p < .001), whereas the control group demonstrated only a slight increase. An Independent Samples t-test confirmed a significant difference between groups at post-test (t = 3.997; p < .001). Conclusion: The study concludes that the Engklek game is an effective and culturally relevant play-based intervention for improving locomotor competence in elementary school students. Integrating traditional games into physical education may provide a cost-effective strategy to promote motor development while preserving cultural heritage.