Despite increased attention on social justice in higher education, underrepresented students often experience the classroom as unwelcoming and even hostile. Although theoretical and pedagogical research exists, what appears to be lacking are examples of concrete social justice pedagogy strategies that can be implemented in the classroom setting. This article describes the Social Justice Syllabus Design Tool (SJSDT) created to facilitate a greater emphasis on social justice in courses. Using an integrative framework and highlighting the focus areas of relationship, community, and process, the SJSDT offers a systematic approach to course re-design by which instructors can assess their classroom environment and course content. A syllabus that signals belongingness, growth mindset, communal goals, clear and positive expectations, and success-orientation assists in setting a welcoming tone that leads to greater student achievement and engagement. Such a syllabus may also help reduce the potential for triggering stereotype threat or other forms of alienation that affect student success among women and students of color in STEM programs. Feedback received from faculty who utilized the tool to revise their course syllabi are discussed, in addition to limitations and recommendations for future practice.