This session explores intersections among archaeological research, heritage conservation, and sustainable development at national and regional scales in Southeast Asia. The region shares historical and ethnocultural ties, yet each country maintains distinct governance of archaeological resources. This session seeks papers that: (1) present new discoveries or reinterpretations relating to historical archaeological heritage, including ancient and early/medieval polities, religion, belief systems, and cultural interaction; (2) assess conservation and management, such as strategies to mitigate environmental and human impacts, community roles, and policy frameworks; (3) analyze sustainable development and heritage economics, including models that generate local value while ensuring long-term protection, equitable stakeholder benefit, and reduced environmental footprint; (4) examine international collaboration and technology, highlighting regional cooperation, digital methods, and remote sensing for research and preservation.