The article considers the phenomenon of martyrdom in the Western nationalisms of the 18th–20th centuries, and is analyzed in three examples. These are the cults of Marat, Lepelletier, Chalier, and other martyrs in France during the 1789 French Revolution; the cult of Abraham Lincoln and other “martyr president” cults in the USA; and the Irish martyrdom ideologies from the 17th century to the 1916 Eastern Rising. The classic studies on nationalism (E. Gellner, B. Anderson, E. Hobsbawm, etc.) do not pay attention to the topic. Other works consider separate cases, though lack a general theory. Thus, the article’s major goals are to discover what is the role of martyrdom in nationalisms, and how is it related to religious ideas. In order to answer these questions, the author proposes a structural, or “compositional”, model, suggesting that the discourse of martyrdom consists of the three motives of founding, militancy, and mobilization. These three components work as an integral “engine” that allows a nationalist movement or a nation-state to fight to create the new reality and preserve what was created. The author suggests that the balance of these three motives in each individual case may differ, so one of the motives may be hypertrophied, while the other two motives are simply “completed” to the minimum level. Proceeding from the fact that martyrdom in nationalisms constantly refers to religious ideas, images, and rituals, the author concludes that martyrdom is an integral phenomenon with no clear borderline between “secular” or “religious” with regard to both individual cases and the elements of a much larger case.