Physical education learning in rhythmic movement activities at primary schools often faces obstacles due to conventional and monotonous instructional methods, directly affecting students' low motivation and physical competence. This study aims to address this research gap by evaluating the implementation of the "Rhythm Detective" game-based learning model and investigating its significant effect on physical education learning outcomes among fifth-grade students at UPT SD Negeri 060886 Medan Baru in the 2025/2026 academic year. A quantitative approach with a one group pretest-posttest design was utilized. The target population comprised 65 fifth-grade students, from which 22 students from class V C were selected as research samples using a purposive sampling technique based on ethical considerations. Data collection techniques involved cognitive-motor tests, student questionnaires, structured classroom observations, and instructional documentation that had satisfied construct validity and reliability standards. The results revealed that the average pre-test score of 50.45 significantly increased to 77.95 in the post-test, supported by an average student questionnaire response of 81.13. Hypothesis testing using paired t-test produced t_"count" =7.502, exceeding t_"table" =1.717 at a significance level of 0.000<0.05, confirming that the alternative hypothesis (H_a) is accepted. In conclusion, the rhythm detective game-based learning model exerts a positive and significant effect on enhancing rhythmic movement learning outcomes, serving as an effective pedagogical alternative for primary school physical education. ABSTRAK Pembelajaran PJOK pada materi gerak berirama di sekolah dasar kerap mengalami kendala akibat model pembelajaran yang konvensional dan monoton, sehingga berdampak pada rendahnya motivasi serta hasil belajar siswa. Penelitian ini bertujuan untuk mengkaji efektivitas penerapan model pembelajaran berbasis permainan "Detektif Irama" dalam menjembatani kesenjangan motivasi belajar tersebut serta mengetahui pengaruhnya terhadap hasil belajar PJOK siswa kelas V UPT SD Negeri 060886 Medan Baru Tahun Ajaran 2025/2026. Penelitian ini menggunakan pendekatan kuantitatif dengan desain eksperimen one group pretest-posttest design. Populasi penelitian mencakup seluruh siswa kelas V yang berjumlah 65 orang, dengan penentuan sampel menggunakan teknik purposive sampling sehingga diperoleh sampel sebanyak 22 siswa pada kelas V C. Teknik pengumpulan data dilakukan melalui tes hasil belajar, angket respon siswa, observasi keterlaksanaan, dan dokumentasi yang telah melalui uji validitas serta reliabilitas. Hasil analisis menunjukkan nilai rata-rata pre-test sebesar 50,45 meningkat secara signifikan menjadi 77,95 pada post-test, disertai rerata angket respon siswa sebesar 81,13. Pengujian hipotesis melalui uji-t menghasilkan t_"hitung" =7,502 yang lebih besar daripada t_"tabel" =1,717 dengan taraf signifikansi 0,000<0,05, sehingga H_a diterima dan H_0 ditolak. Dengan demikian, model pembelajaran berbasis permainan Detektif Irama terbukti memberikan pengaruh positif dan signifikan terhadap peningkatan hasil belajar gerak berirama siswa sekolah dasar.