This is an Open access book which provides insights into innovative approaches in designing, implementing, and evaluating professional development programs for English-Medium Instruction (EMI) faculty. It offers empirically-grounded solutions to the pressing challenge of supporting faculty who teach disciplinary content through English in non-Anglophone contexts, addressing the current lack of an established paradigm for effective EMI faculty development practices. As EMI expands globally across higher education institutions, faculty face complex linguistic, pedagogical, and disciplinary demands that call for targeted professional support. However, limited research exists exploring specific design and implementation features of faculty development programs and their impact on teaching practices and student outcomes. The volume bridges these crucial gaps by showcasing original empirical studies that demonstrate clear connections across program design choices, implementation strategies, and resulting effects on faculty instructional practices and decision-making. Featuring in-depth case studies from diverse institutional and sociocultural settings in Asia, Europe, and Latin America, the collection offers unique perspectives on how faculty developers have addressed the shared challenge of supporting EMI faculty professional development. The book features diverse methodological approaches - including qualitative, quantitative, and mixed-methods studies - that foreground multiple aspects of EMI faculty development: collaborative practices within professional development initiatives, innovative approaches to pedagogy integrating language and content support, institutional frameworks for sustainable implementation, and longitudinal analysis of program impact on teaching and learning. The contributing authors expand the conceptual and disciplinary foundations of EMI faculty development research by drawing on their diverse scholarly perspectives from educational psychology, applied linguistics, second language studies, STEM education, and educational policy and leadership, as well as their lived experiences in developing, implementing, and assessing professional development initiatives. The volume aims to provide evidence-based guidance for creating sustainable and effective support for EMI faculty development and contribute to paradigm-building in EMI. It is poised to be essential reading for multiple audiences in global higher education, including EMI researchers, faculty developers, language educators, higher education administrators, and graduate student researchers.