By using three main concepts, namely geopolitical agents, geopolitical structures, and geopolitical codes, this study examines how the geopolitics of Southeast Asia after the Indo-Pacific initiative in 2007, especially in the framework of the ASEAN Outlook on Indo-Pacific. Assessing qualitatively-descriptively through analyzing data from various books, journals and credible websites, the authors argue that, apart from ASEAN, there are also a number of actors/agents in the form of countries that have influence in the geopolitical structure, especially in Southeast Asia and even in the Indo-Pacific in general, namely Singapore, Indonesia, the Philippines, Thailand and Malaysia. The concepts of The Free and Open Indo-Pacific (FOIP) and the ASEAN Outlook on Indo-Pacific (AOIPs) have also been part of the Indo-Pacific geopolitical structures. While the Philippines and Singapore tend to take sides in supporting the US Indo-Pacific idea, some of the other actors, namely Thailand, Malaysia, Myanmar, Laos, Cambodia, actually show a neutral position.