Introduction The Southeast Asian peninsula is made up of the countries that are geographically positioned south of China, north of Australia, and east of India. The peninsula occupies a landmass of 5 million square kilometers. Southeast Asian people share a number of somatic characteristics. However, there are significant variations in relation to population size, religion, ethnic groups, languages, culture, and forms of government adopted in different regions. The total volume of trade and services emanating from the region was estimated at $1.7 trillion as of 2008 (International Energy Agency 2013). On its part, the average GDP was pegged at over $1.5 trillion (Williams and Guest 2015, 12). Southeast Asia is viewed as the next growth engine in the Asian peninsula. For example, in 2015, the Asian Development Bank observed that the economies of Malaysia, Indonesia, Philippines, Vietnam, and Thailand are estimated to grow by 6% by 2030 (Williams and Guest 2015, 78). The five countries have a combined population of approximately 525 million and a GDP of $2.8 trillion. In this research paper, the author will analyze the link between energy security, sustainability, and economic growth in Southeast Asia. To this end, the author will review urbanization in this region and how energy spurs economic growth. Energy Security, Sustainability, and Economic Growth in Southeast Asia Overview For a long time, the growth of the Southeast Asian peninsula has been eclipsed by China and India. However, the GDP of the peninsula was almost equal to that of India in 2015. It is estimated that the region could overtake Japan within a few decades. To support the rapidly growing ASEAN economy, the countries need to harness their energy capacity. As of 2012, the demand for energy was outstripping production (Williams and Guest 2015, 36). It is also observed that the coal and onshore oil resources in this region are on the decline after years of exploitation and reduced investment. The ASEAN countries have resorted to the importation of energy as they explore new sources of the resource. Urbanization in Southeast Asia Most parts of the Southeast Asian region have experienced rapid urbanization in the recent past. The development is mainly driven by industrialization, as well as the globalization of the region’s economic activities. Most of the immigrants living in the cities are drawn from rural areas. The increased production, which is brought about by industrialization, a fall in transport costs, and strong export-oriented economies, has fostered the growth of urban centers across Southeast Asia (Williams and Guest 2015, 39). The rapid urbanization has led to overcrowding in most of the urban centers. The growth in infrastructure does not match the rise in the needs of the population. Consequently, an expansion of the informal settlements in the cities has presented a serious risk to the inhabitants (McGee 2007, 277). The people living in these informal settlements are poor. They also lack food and have no access to safe water. In addition, hygiene facilities are non-existent, which is a danger to human life. The urbanization has also led to the growth of what is referred to as the extended metropolitans (Hong and Lugg