This PhD thesis explores a history of multiple visions of Socialist construction as articulated by Soviet architects, mainly but not exclusively in the Khrushchev era. Most commonly, Soviet architecture of this era is associated with the return of modernist aesthetics into the architectural practice of the Soviet Union. I question both these elements: whether there was a return and whether it was to modernism. In order to examine these questions I focus on Soviet architects and their visions and trace the evolution of professional discourses and practices across the rupture of 1954 spanning the period from the early 1930s to the late 1960s. Rather than thinking of architecture simply as an aesthetic discourse and building practice that either represented the regime or failed to do so, this thesis deals with architecture as a fundamental component of the revolutionary project of building Socialism, part and parcel of the state-driven program to make the physical and social landscape of the Soviet Union modern . I refer to the professional aspirations and imperatives of Soviet architects embedded in this revolutionary project as 'Socialist Modern'. Simply put, I show that there were many synchronic and diachronic visions of Socialist Modern. In particular, in chapter one I revisit the era after 1932 in Soviet architecture, a time of radical departure from the principles of modern architecture, and demonstrate how different understandings of modern architecture co-existed. Chapter two analyses how these divergent visions resurfaced and clashed after Khrushchev announced a radical shift to mass construction in 1954, which allows us to see this time as not merely one of ruptures and impositions of new rules from the top but as a history of equally important continuities established by Soviet architects themselves. In chapters three and four I examine two synchronic visions for Socialist Modern, the pragmatic design for Novye Cheriomushki and the visionary project of NER, which originated from different sources and constituted two different programs for the future of Soviet architecture. Chapter five traces how the pragmatic vision articulated in the Cheriomushki project evolved into Soviet mainstream and later into what I call Generic Modern and how the NER vision developed into a full-blown alternative that I call Organic Modern. Based on so far unexplored archival sources, the professional press and memoirs, this study challenges the prevailing emphasis on ruptures in Soviet architecture and constitutes a first step in mapping the diversity of Socialist Modern within the Soviet Union and within the Second World.