During the second half of the nineteenth century, Paris and London underwent major urban transformations. Public and private spaces evolved jointly, and both gave an increasingly important place to entertainment and spectacle. At the crossroads of all the arts, the theatrical stage initiated unprecedented collaborations between artists of all disciplines, but also between artists and decoration firms. Through a symbolic reading of objects, fashions and patterns, the theatre promoted new ways of conceiving the set, of reading it and of existing within it. It was both the reflection and the driving force of the evolution of the decorative arts. From the stage to the domestic interior, and through exhibitions, shops and museums, the theatricalisation of decoration took over all the spectacular spaces of this period. Through the study of the mise en scène in its theoretical conception, its visual aspect and its materiality, this thesis proposes a common analysis of décors between stage and interior. It raises the question of the relationship of individuals to the materiality that surrounds them, highlights the circulation of decorative arts around the theatre, and proposes a reinterpretation of the history of the decorative arts of the second nineteenth-century by including the significant role of the performing arts.