Abstract: In this study, the authors examine mythology and ideology, their nature and origin, as well as the processes of their relationship. It is argued that ideology and mythology are in many ways interrelated phenomena, but not reducible to each other. Between them, not imperative, but rather complimentary relations are established, when they borrow certain elements and structures of each other in the process of interaction. The commonality of their nature and origin is manifested in the commonality of their properties and functions. Ideology has two sides: rational and irrational. The study shows that the irrational side of ideology is no less important and has no less influence on the final consumers of ideology than its rational and scientific elements. The irrational side is expressed in the mythical, unconscious, affective and imaginary. The scientific novelty of the study consists in revealing the essence of ideological myths, designating myths in the structure of ideology, establishing the "mythomotorics" of ideology, as well as highlighting the main properties of ideology and mythology: spontaneity and chaotic origin; unorganised and a-centric character; deployment in different social fields and dimensions; transmission of the same message through several codes; comprehensive and all-encompassing impact on end-users; lack of complete clarity and eluding analysis; ritual and repetition. It is concluded that the functional role of myths in ideology is that they fill the void between the ideological system and the social order in places where they do not correspond or openly contradict each other.