Financial technology, aka Fintech, is poised to be the driving force of Southeast Asian economies in the future. While there are numerous studies of the development of Fintech in each ASEAN country, there has been a noticeable absence of a comprehensive report encompassing those nations as a whole. Hence, this report aims to scrutinize and analyze the development of Fintech in those ten nations in various aspects such as market size, Fintech adoption rate, types of Fintech, main players, new start-ups, technical infrastructure, government policy and regulation, the impact of Fintech on the local economy, security concern, and future trends meticulously. In order to achieve this objective, this study mainly uses a systematic review methodology with data from various trusted secondary sources such as governmental agencies, the World Bank, and academic studies. The results also reveal that Fintech in most ASEAN countries has grown significantly during the past years. Furthermore, specific recommendations for governments to foster their respective Fintech markets will be proposed.