Southeast Asia (SEA) is one of the fastest developing regions in the world with energy demand projected to grow by 60% over the next 20 years. Indonesia, Philippines, Thailand, and Vietnam represent nearly three-quarters of total power generation in Southeast Asia, and account for about 72% of the region’s GDP and for 82% of its population; therefore, the ability of the region to meet its development goals largely depends on these countries’ current and future energy choices. Despite sustained deflationary global trends and the potential of renewable energy in the region, fossil fuels remain SEA’s dominant source of energy, subjecting the region’s economies to deep long-term economic and environmental risks. Several barriers hinder the scaling up of renewables including inconsistent energy planning, inappropriate consideration of their and energy efficiency potential, grid capacity and stability concerns, lack of cross border integration of power systems as well as political economy dynamics that favour incumbent fossil technologies. SEA is a key region to drive global climate action and to achieve the Paris Agreement objective. Limiting temperature increase to 1.5°C would avoid the worst impacts of climate change. To reach this objective, the use of renewable energy should be rapidly increased with the aim to complete a total phase-out of coal by 2050 at the latest.