Since the development of Islam in the 13th century in Southeast Asia, the traders who came from Arabia and Persiainitially spread the religion using peaceful means rather than by violence. However, the current condition of thedevelopment of Islam in Southeast Asia are stained by acts of terrors carried out by various Lone Wolf where someof them have experienced violent jihad in other countries such as Iraq and Syria. Their losses in the battlefield forcedthem to return to their countries as returnees. These Lone Wolf returnees problem has quickly become a worldwideconcern, especially with various evidence that they are related to recruitment and suicide bomber activities inSoutheast Asia. As the results of social media propaganda on the Internet they obtain new followers such as thesupport of young people from Thailand, Malaysia, the Philippines and Indonesia. The purpose of this study is toanalyze and uncover the development of Lone Wolf Terrorism in Southeast Asia. The results of this study include:First, identifying the forms of threats of Lone Wolf Terrorism in Southeast Asia which are divided into three typesof threats, namely the first, second, and third generations of terror. Second, revealing the Lone Wolf Terrorismnetwork on the Internet that is filled with propaganda to attract sympathy of younger generation to join the Al-Qaeda,ISIS, and Islamic State (IS) networks. Third, Analyzing the IS Terror Network in Southeast Asia by revealing theactivities and organizational structure of Al-Qaeda, ISIS, and IS.