This qualitative research investigates the developing patterns of outbound tourism in emerging Southeast Asia's source markets, with five selected countries as the subject: the Philippines, Vietnam, Malaysia, Thailand, and Singapore. Southeast Asia has traditionally been considered a destination area, but it is also emerging as an important source of the world's outbound tourist flows. Following the PRISMA systematic document selection guide and using NVivo to code thematically, this study read peer-reviewed articles, regional reports, and national tourism reports from 2018 to 2024. It identified five overarching themes through analysis: air travel accessibility and economic mobility, government initiatives in promoting tourism, diaspora role in driving travel demand, digital travel platforms and social media, and regional integration and visa policies. Results present the Philippines as one of the high-growth outbound source markets, underpinned by policy liberalization, the expanding middle class, and robust diaspora networks. Comparative cross-country observations indicated travel motivation and behaviour differences, shaped by socio-economic profiles, government policy, and digital lifestyles. This research presents a comparative qualitative model of Southeast Asian outbound tourism studies and practical knowledge for policymakers and industry stakeholders. It emphasizes the importance of regional collaboration, data exchange innovation, and creating targeted outbound travel campaigns to allow Southeast Asia to take its place as a source region globally.