The blue economy has emerged as a strategic framework for reconciling ocean-based economic development with marine ecosystem conservation and social well-being, particularly in maritime regions such as Southeast Asia. As one of the world’s most ocean-dependent regions, the Association of Southeast Asian Nations (ASEAN) possesses extensive marine resources that support fisheries, marine tourism, shipping, offshore energy, and emerging marine biotechnology industries. This review critically synthesizes the development, governance, challenges, and future prospects of the blue economy across the ten ASEAN member states. A total of 40 peer-reviewed journal articles published between 2010 and 2024 were systematically reviewed and organized into four thematic areas: (i) the sectoral composition and economic contribution of blue economy activities; (ii) policy, institutional, and governance frameworks; (iii) environmental and socioeconomic constraints; and (iv) emerging pathways toward sustainable and inclusive ocean-based development. The synthesis indicates that ASEAN’s ocean-based sectors collectively generate an estimated USD 360–380 billion annually, demonstrating their substantial contribution to regional economies. However, their long-term sustainability remains constrained by fragmented governance, marine ecosystem degradation, unsustainable resource exploitation, uneven institutional capacity, and inequitable distribution of economic benefits. Significant differences among member states further highlight the need for context-specific national strategies supported by stronger regional coordination. Future blue economy development should prioritize integrated ocean governance, sustainable blue finance, technological innovation and transfer, ecosystem-based management, and meaningful participation of coastal communities. Strengthening these mechanisms would enable ASEAN to move beyond sector-driven ocean exploitation toward a more resilient, inclusive, and environmentally sustainable blue economy while accelerating progress toward Sustainable Development Goal 14 (SDG 14: Life Below Water) and the broader 2030 Agenda.