Ideology has been regarded as one of the motivational causes of terrorism. In fact, the ideology is not what motivates people to turn to terrorism as a means to achieve political ends, but it is used as a legitimizing tool for the terrorist acts in the eyes of the public. This article aims to display the relationship between the ideologies and the terrorism, and precisely how ideologies are used for terrorist purposes. Within the scope of this article, types of terrorism, classified in terms of ideological motivations, namely left-wing, right-wing, separatist and religious terrorism, are explored. The changing profile of terrorism is also touched upon with reference to ideological shifts, and how these reflect on the terrorist organizations and their acts.