This article comprehensively examines the historical and political retrospective of the concepts of religious extremism and terrorism. The authors studied in detail the essence of the terms "extremism" and «terrorism», analyzed their ideological concepts. In the article, the authors considered the concepts of religious extremism and terrorism, and also used the methods and techniques of structural-functional, historical and comparative methodology to reveal their essence. This article was prepared in the framework of the research project BR05236488 «Formation of Kazakhstan's Identity in the Context of Modernization of Public Consciousness».