Abstract: This study aims to determine the effect of the Discovery Learning model with the Teaching at the Right Level (TaRL) approach on the mathematical critical thinking skills of grade XI students. The research was conducted in the first semester of the 2025/2026 academic year using a quasi-experimental design with a pretest-posttest control group design. The sample was selected using a simple random sampling technique, consisting of two classes: one experimental class that received Discovery Learning with the TaRL approach and one control class that received conventional learning. The research instrument consisted of four essay-type questions designed to measure mathematical critical thinking skills, including the indicators of interpretation, analysis, evaluation, and inference. Descriptive analysis showed differences in achievement between the two classes. The average pretest score of the control class was 55.00, while the experimental class scored 42.36. After treatment, the average posttest score of the control class increased to 61.98, whereas the experimental class reached 72.74. The results of normality and homogeneity tests indicated that the data were not normally distributed but homogeneous. Therefore, hypothesis testing was conducted using the non-parametric Mann-Whitney test, which yielded a significance value of 0.0025 (<0.05). This result indicates that the Discovery Learning model with the Teaching at the Right Level approach has a better effect on students’ critical thinking skills than conventional learning among grade XI students at SMA Negeri 1 Sunggal.  Keyword: Discovery Learning, Teaching at the Right Level, Critical Thinking Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh model pembelajaran Discovery Learning dengan pendekatan Teaching at the Right Level terhadap kemampuan berpikir kritis matematis peserta didik kelas XI. Penelitian ini dilaksanakan pada semester ganjil tahun ajaran 2025/2026 dengan menggunakan desain penelitian quasi experiment tipe pretest-posttest control group design. Sampel penelitian diambil dengan teknik simple random sampling dan ditetapkan dua kelas, yaitu satu kelas sebagai kelas eksperimen yang mendapatkan pembelajaran Discovery Learning dengan pendekatan TaRL, serta satu kelas sebagai kelas kontrol yang memperoleh pembelajaran konvensional. Instrumen yang digunakan berupa tes uraian sebanyak 4 butir soal yang mengukur kemampuan berpikir kritis matematis meliputi indikator interpretasi, analisis, evaluasi, dan inferensi. Analisis deskriptif menunjukkan adanya perbedaan capaian antara kedua kelas. Nilai rata-rata pretest peserta didik di kelas kontrol adalah 55,00 dan di kelas eksperimen 42,36. Setelah perlakuan, rata-rata skor posttest kelas kontrol meningkat menjadi 61,98, sedangkan kelas eksperimen mencapai 72,74. Hasil uji normalitas dan homogenitas menunjukkan bahwa data tidak berdistribusi normal dan data homogen. Oleh karena itu, pengujian hipotesis menggunakan uji non-parametrik Mann-Whitney yang menghasilkan nilai signifikansi 0,0025 (<0,05). Hal ini menunjukkan bahwa pengaruh model pembelajaran Discovery Learning dengan pendekatan teaching at the right level lebih baik dari pembelajaran biasa terhadap kemampuan berpikir kritis peserta didik kelas XI di SMA Negeri 1 Sunggal. Kata kunci: Discovery Learning, Teaching at the Right Level, Berpikir Kritis