Masalah rendahnya kemampuan berpikir reflektif matematis siswa perlu dipecahkan. Penelitian ini bertujuan menganalisis peningkatan kemampuan pemikiran reflektif matematika siswa yang belajar menggunakan model Brain-based Learning dan Discovery Learning. Metode penelitian yaitu eksperimen dengan pretest dan posttest tak ekuivalen. Penelitian dilakukan di salah satu Sekolah Menengah Pertama Islam di Kota Sumedang. Populasi penelitian yaitu seluruh siswa kelas VIII, dengan sampel kelas VIII A (kelas eksperimen) dan kelas VIII B (kelas kontrol). Data diperoleh dari tes pemikiran reflektif matematika dan kuisioner siswa. Hasil analisis menunjukkan bahwa peningkatan keterampilan pemikiran reflektif matematika siswa yang belajar menggunakan model Brain-Based Learning lebih baik daripada mereka yang belajar menggunakan model Discovery Learning. Siswa juga memberikan tanggapan positif terhadap penggunaan Brain-based Learning. Model Brain-Based Learning dapat menjadi alternatif dalam meningkatkan keterampilan pemikiran reflektif matematika siswa.The problem of low students' mathematical reflective thinking skills needs to be solved. This study aims to analyze the increase in students' mathematical reflective thinking skills who learn to use Brain-based Learning and Discovery Learning models. The research method is experimentation with non-equivalent pretest and posttest. The research was conducted at one of the Islamic Junior High Schools in Sumedang City. The research population was all students of class VIII, with samples from class VIII A (experimental class) and class VIII B (control class). The data were obtained from tests of mathematical reflective thinking and student questionnaires. The results of the analysis show that the improvement of students' mathematical reflective thinking skills who learn to use the Brain-Based Learning model is better than those who learn to use the Discovery Learning model. Students also gave positive responses to the use of Brain-based Learning. The Brain-Based Learning model can be an alternative to improving students' mathematical reflective thinking skills.