<![CDATA[ABSTRACT Critical thinking skills are a crucial competency for students facing the challenges of 21st-century learning. Problem-Based Learning (PBL) and Project-Based Learning (PjBL) models are considered capable of enhancing these skills through student-centered instruction. This study aims to analyze the effectiveness of implementing PBL and PjBL in developing students' critical thinking skills using a Systematic Literature Review (SLR) approach. The research methodology adheres to the PRISMA 2020 guidelines, involving the identification, screening, eligibility assessment, and inclusion of articles sourced from Scopus, ScienceDirect, SpringerLink, ERIC, Google Scholar, and SINTA databases for the period 2015–2025. Twenty-five articles meeting the inclusion criteria were analyzed descriptively and comparatively. The findings indicate that both PBL and PjBL consistently exert a positive influence on the improvement of students' critical thinking skills. PBL is more effective in fostering skills related to problem analysis, information evaluation, and logical decision-making, whereas PjBL excels in developing creativity, collaboration, communication, and critical thinking through the completion of contextual projects. The integration of digital media and educational technology has also been shown to enhance the effectiveness of both models. However, implementation still faces challenges regarding time constraints, teacher readiness, and student participation. Thus, PBL and PjBL serve as viable, innovative instructional strategies for enhancing students' critical thinking skills. Keywords: Problem-Based Learning, Project-Based Learning, Critical Thinking Skills ABSTRAK Keterampilan berpikir kritis merupakan salah satu kompetensi penting yang harus dimiliki siswa dalam menghadapi tantangan pembelajaran abad ke-21. Model pembelajaran Problem Based Learning (PBL) dan Project Based Learning (PjBL) dinilai mampu meningkatkan kemampuan tersebut melalui pembelajaran yang berpusat pada siswa. Penelitian ini bertujuan untuk menganalisis efektivitas penerapan PBL dan PjBL dalam mengembangkan keterampilan berpikir kritis siswa melalui pendekatan Systematic Literature Review (SLR). Metode penelitian mengacu pada pedoman PRISMA 2020 dengan proses identifikasi, penyaringan, kelayakan, dan inklusi artikel yang diperoleh dari database Scopus, ScienceDirect, SpringerLink, ERIC, Google Scholar, dan SINTA pada rentang tahun 2015–2025. Sebanyak 25 artikel yang memenuhi kriteria inklusi dianalisis secara deskriptif dan komparatif. Hasil kajian menunjukkan bahwa PBL maupun PjBL secara konsisten memberikan pengaruh positif terhadap peningkatan keterampilan berpikir kritis siswa. PBL lebih efektif dalam melatih kemampuan menganalisis masalah, mengevaluasi informasi, dan mengambil keputusan secara logis, sedangkan PjBL lebih menonjol dalam mengembangkan kreativitas, kolaborasi, komunikasi, serta berpikir kritis melalui penyelesaian proyek kontekstual. Integrasi media digital dan teknologi pembelajaran juga terbukti meningkatkan efektivitas kedua model. Namun, implementasinya masih menghadapi kendala berupa keterbatasan waktu, kesiapan guru, serta partisipasi siswa. Dengan demikian, PBL dan PjBL dapat dijadikan alternatif strategi pembelajaran inovatif untuk meningkatkan keterampilan berpikir kritis siswa. Kata Kunci: Problem Based Learning, Project Based Learning, Keterampilan berpikir kritis]]>
