Penelitian ini bertujuan untuk mendeskripsikan pengaruh pendekatan pembelajaran realistik dan saintifik terhadap prestasi belajar, kemampuan penalaran matematis, dan minat belajar. Jenis penelitian ini adalah quasi experiment dengan pretest-posttest nonequivalent group design. Sampel penelitian adalah tiga kelas yang dipilih secara acak dari enam kelas yang ada. Instrumen yang digunakan adalah tes prestasi belajar, tes kemampuan penalaran matematis, dan angket minat belajar. Untuk menguji keefektifan pendekatan pembelajaran realistik dan saintifik serta pembelajaran konvensional menggunakan uji t one sample. Hasil penelitian menunjukkan bahwa pendekatan pembelajaran matematika realistik efektif terhadap prestasi belajar, kemampuan penalaran matematis, dan minat belajar; pendekatan pembelajaran saintifik efektif terhadap prestasi belajar dan minat belajar tetapi tidak efektif terhadap kemampuan penalaran matematis; sedangkan pembelajaran konvensional tidak efektif terhadap prestasi belajar, kemampuan penalaran matematis, dan minat belajar. Pendekatan pembelajaran realistik dan saintifik memberikan berpengaruh yang lebih efektif dibandingkan dengan pembelajaran konvensional terhadap prestasi belajar, kemampuan penalaran matematis, dan minat belajar. Pendekatan pembelajaran realistik lebih efektif daripada pendekatan saintifik terhadap prestasi belajar kemampuan penalaran matematis, dan minat belajar. Kata Kunci: Pendekatan realistik, pendekatan saintifik, prestasi belajar, kemampuan penalaran matematis, minat belajar The Effect of Teaching Realistic and Scientific Mathematics Approach on Students Learning Achievement, Mathematical Reasoning Ability, and InterestAbstract This study aims to describe the effect of realistic and scientific approach on student’s learning achievement, mathematical reasoning ability, and interest. This study is a quasi-experimental study using the pretest-posttest nonequivalent group design. The research sample was randomly selected from six classes, three classes were elected. The instrument used in this study is the learning achievement test, a test of mathematical reasoning ability, and an interest-in-learning questionnaire. To test the effectiveness of teaching realistic and scientific mathematics approach, as well as conventional teaching using one sample t-test. The research findings indicate that the teaching realistic mathematics approach is effective on student’s learning achievement, mathematical reasoning ability, and interest; the teaching scientific approaches is effective on student’s learning achievement, and interest, but is not effective in mathematical reasoning ability; whereas conventional teaching is not effective on students learning achievement, mathematical reasoning ability, and interest. The teaching realistic and scientific mathematics approach has an effect and is more effective than conventional teaching on student’s learning achievement, mathematical reasoning ability, and interest. The realistic mathematics approach is more effective than a scientific approach on student’s learning achievement, mathematical reasoning ability, and interest. Keywords: realistic approach, scientific approach, academic achievement, mathematical reasoning ability, interest in learning