The article explores the development of e-commerce logistics in the Greater Mekong Subregion as an example of digital transformation of economic and commercial activity in Southeast Asia. On reviewing the present state and the dynamics of e-commerce-related processes in Southeast Asia, the paper points out salient features of regional economic growth initiatives in synergy with the priorities of the ASEAN Economic Community (AEC) 2025. The substantial and the institutional dimension of the Greater Mekong Subregion (GMS) are discussed in detail. The paper finally turns to analyzing the GMS transport and logistics component in connection with e-commerce practices across the GMS area. The article does not aim to discuss the e-commerce and the economic corridors of the GMS apart from each other, which has been done by other researchers. Instead, the analytical focus of the paper, namely, a synergy between e-commerce, transport and logistics exemplified by the GMS cooperation, accounts for its academic novelty. The author argues that owing to the resources and assets that move beyond digitalization per se, China is likely to be the key beneficiary of the current demand for synergizing e-commerce with transport and logistics transnational infrastructure shared by Southeast Asia. Although this conclusion confirms earlier assessments, the GMS e-commerce logistics example convincingly demonstrates that Southeast Asia increasingly becomes a PRC-oriented area of economic and commercial activity.