The article discusses the need for a paradigm shift in ASEAN's energy diplomacy to navigate the challenges posed by energy transition in Southeast Asia. As fossil fuels have historically dominated the region's energy landscape, there is a pressing need to transition towards renewable sources to achieve national net-zero targets and combat global warming. Renewed focus on renewable energy diplomacy is highlighted as a catalyst for sustainable energy development. Examples such as Singapore's commitment to importing low-carbon electricity and Vietnam's collaboration on wind and solar energy signify a growing alignment of energy transition with diplomatic strategies within the region. However, ASEAN faces hurdles related to trust deficits, resource nationalism, and the US-China rivalry over critical minerals essential for green technologies. To address these challenges, ASEAN must foster consensus among its members to establish a regional institution that can enforce agreements, resolve disputes, and enhance data sharing. Additionally, mitigating the negative impacts of the US-China rivalry on critical mineral supply chains is crucial. Collaborative efforts within ASEAN and with external partners are essential in navigating the complex geopolitics of energy transition. The article emphasizes the importance of integrating renewable energy diplomacy into ASEAN's political frameworks to bolster energy security and combat climate change effectively. By recognizing the significance of diplomatic strategies in accelerating the energy transition, ASEAN can pave the way for a sustainable and secure energy future in the region.