Science, technology, engineering, and mathematics (STEM) has an important role in ensuring inclusive and equitable quality education and promoting lifelong learning opportunities for all. By utilizing an inquiry- based and experiential teaching and learning approach as well as integrating engineering and technology with science and mathematics, STEM promotes employability skills, entrepreneurship, and innovation. This publication presents case studies on the successful application of STEM in Thailand, the Republic of Korea, Singapore, and Finland. It aims to provide inspiration and lessons for developing member countries of the Asian Development Bank to enhance and develop their respective STEM education programs.