This study aims to develop a differentiated neuroscience-based learning approach using a project-based model to improve students' critical thinking skills, including research and development with adapted procedures from Robert Reiser and Michael Molenda through five stages. The initial field test sample consisted of 36 seventh grade students of Darussalam Elementary School, Jombang, with an experimental class of 36 students (VII A) and a control class of 34 students (VII B). Data collection tools included questions measuring critical thinking skills, student response questionnaires, and observation sheets for learning implementation, with data analysis using MANOVA at a significance level of 5%. This study successfully developed a neuroscience-based, differentiated project-based learning model to enhance critical thinking in Arabic instruction. Following Reiser and Molenda’s five-stage R&D procedure, the analysis identified teacher-centered limitations and students’ weak analytical skills. The design produced differentiated materials for visual, auditory, and kinesthetic learners, interactive multimedia, and validated assessment tools. Development yielded a complete guide with a three-meeting lesson plan and tiered worksheets. Implementation in grade VII featured Self-Introduction Vlog and Dream Career Fair projects, applying content, process, and product differentiation. MANOVA results confirmed significant improvements in analysis, evaluation, and creativity. The model effectively integrates cognitive load principles, supports individual needs, and bridges rote and meaningful learning while strengthening teachers’ pedagogical competence.