The Russian avant-garde was a unique phenomenon of the transitional culture of the early 20th century, representing a holistic aesthetic system that combined radical artistic experiments, social utopia, and industrial progress. This is a new historical era, when artists, losing their status as individual creators, saw art as a means of shaping a new world and a “new” human. Now art supposed to serve society by fulfilling practical tasks. For costume, which became a symbol of transformative influence in the new conditions, the ideas of industrial art, constructivism, and suprematism proved to be truly declarative. The analysis of these trends formed the basis of this research. It is based on a combination of formal-stylistic and iconographic analysis, comparative and semiotic approaches. As a result, the new aesthetics of Russian avant-garde costume clearly demonstrated. Its basis consisted of three interconnected principles: functionality (the central principle of the theory of production art), the geometrization of the silhouettes (straight silhouette and rectangular cut, emphasis on the shoulder line, simplification and schematization), and combinability. At the same time, the visual language of the avant-garde is analyzed: contrasting color blocks, suprematist ornament, and the incorporation of alphanumeric elements that turned the costume into a means of visual communication and agitation. All design elements – from construction to color – were subordinated to the ideological tasks of unification, collectivity, dynamism, and revolutionary optimism (understood here as the modular principle, universality and economy, having ideological significance). The new aesthetic was a response to the social and economic challenges of the era.