This report covers 21 smart cities case studies in cities across the Southeast Asian region which includes 10 countries (Vietnam, Cambodia, Thailand, Indonesia, Singapore, Brunei, Malaysia, Myanmar, Laos, and the Philippines). While most of the focus is centered on megacities like Bangkok, Manilla, Kuala Lumpur, Jakarta, Hanoi, Ho Chi Minh City, Phnom Penh, and Singapore, projects in smaller cities are also covered. Smart cities programs, initiatives, partnerships, and associations on local, national, and international level are analyzed next to country-specific smart cities needs, challenges, and requirements against diverse social, cultural, political, and economic contexts. Technology suppliers are discussed from a project implementation perspective with key vendors such as ABB, Cisco, Alibaba, Siemens, Fujitsu, and Dassault Systemes.