This article investigates how Project‑Based Learning (PBL) can be systematically embedded in undergraduate translation courses to nurture collaboration and critical thinking among English majors. Treating translation as decision-making under constraints, the study argues that learning should be organized around authentic briefs, iterative drafts, and audience feedback instead of isolated exercises and after‑the‑fact corrections. Integrating constructivism, sociocultural theory, and cognitive apprenticeship, the study outlines a course architecture that aligns outcomes, evidence, and experiences through backward design. The study then details four classroom‑tested project types: community‑facing localization, institutional document translation, literary micro‑anthology, and multimodal subtitling with accessibility, each with roles, milestones, scaffolds, and deliverables. A mixed‑methods evaluation plan connects artifacts such as decision memos, risk registers, and tracked‑changes files to rubrics for collaboration and critical thinking. The study also discusses risks and mitigation, including workload, fairness, and responsible tool use. The study concludes that PBL, when properly scoped and supported, turns collaboration and critical inquiry from occasional by‑products into the engine of translation learning, improving both the quality of texts and the transparency of the reasoning that produces them.