The article considers the processes of evolution of ethnic terrorism during the XIX-XX centuries. It is noted that the emergence of ethnic terrorism is associated with the growth of nationalism and the rise of national movements. The article shows the relationship between ethno-political conflicts and ethnic terrorism. It is emphasized that ethnic conflicts are often intertwined with socio-political conflicts. The article considers the influence of left-wing revolutionary terrorism on ethnic terrorism both when it only began and in the subsequent historical periods. The article analyzes the impact of left-and right-wing ideological trends on ethnic terrorism. The article considers the ideological and political platform and activities of various ethnic terrorist organizations. It is stated that the specific forms and ideological and political orientations of ethnic terrorism depend on the socio-political situation in a particular country and on the trends that dominate the world politics at various historical periods.