Abstract: 21st century learning is an approach that prioritizes the development of critical skills such as creative thinking, collaboration, and problem solving. The Problem Based Learning (PBL) model in 21st century learning effectively develops these skills and improves student learning outcomes. This study aims to determine the effect of problem-based learning model on creative thinking skills and biology learning outcomes of science class XI students at MAN 1 Mataram. This research was conducted using the non-equivalent control group design method and the sampling technique was purposive sampling method, namely class XI IPA 3 as the experimental class and XI IPA 2 as the control class. The instrument used to measure creative thinking skills is a test in the form of essay questions with a total of 4 questions and learning outcomes are measured using a test in the form of multiple choice questions with a total of 15 questions. The indicators of creative thinking skills are fluency, flexibility, originality and elaboration. The data were analyzed using non-parametric statistical tests, namely using the Man-Whitney test with the help of the SPSS 25 for windows application. The results of creative thinking skills research obtained Sig value. (ɑ) = 0.000 <0.05, while the learning outcomes obtained Sig. (ɑ) = 0,002 < 0,05. From the results of the study it can be concluded that the problem-based learning model has a significant effect on creative thinking skills and learning outcomes. Keywords: Problem Based Learning, Creative Thinking Skills, Learning Outcomes. Abstrak: Pembelajaran abad 21 adalah pendekatan yang mengutamakan pengembangan keterampilan kritis seperti berpikir kreatif, kolaborasi, dan pemecahan masalah. Model Problem Based Learning (PBL) dalam pembelajaran abad 21 efektif mengembangkan keterampilan tersebut dan meningkatkan hasil belajar siswa. Penelitian ini bertujuan untuk mengetahui pengaruh model problem based learning terhadap keterampilan berpikir kreatif dan hasil belajar biologi siswa kelas XI IPA di MAN 1 Mataram. Penelitian ini dilakukan dengan menggunakan metode non-equivalent control grup design dan teknik pengambilan sampel yaitu dengan metode purposive sampling, yakni kelas XI IPA 3 sebagai kelas eksperimen dan XI IPA 2 sebagai kelas kontrol. Instrumen yang digunakan untuk mengukur keterampilan berpikir kreatif adalah tes berupa soal essay dengan jumlah 4 soal dan hasil belajar diukur dengan menggunakan tes berupa soal pilihan ganda dengan jumlah 15 soal. Adapun indikator keterampilan berpikir kreatif yaitu kelancaran (fluency), keluwesan (flexibility), keaslian (originality), dan merinci (elaboration). Data dianalisis menggunakan uji statistik non parametrik yaitu menggunakan uji Man-Whitney dengan bantuan aplikasi SPSS 25 for windows. Hasil penelitian keterampilan berpikir kreatif diperoleh nilai Sig. (ɑ) = 0,000 < 0,05, sementara hasil belajar diperoleh nilai Sig. (ɑ) = 0,002 < 0,05. Dari hasil penelitian dapat disimpulkan bahwa model problem based learning berpengaruh signifikan terhadap keterampilan berpikir kreatif dan hasil belajar biologi siswa. Kata Kunci: Problem Based Learning, Keterampilan Berpikir Kreatif, Hasil Belajar.