Narkomtiazhprom, unbuilt constructivist administrative complex in Moscow, Russia

The Narkomtiazhprom Building was an unbuilt 1934 competition design for the People's Commissariat of Heavy Industry, meant for the site of the Upper Trading Rows (now GUM) on Red Square. The winning entry by Ivan Leonidov proposed three slender towers, while the building was to span over 400 metres along the square, with a built-out area of 40,000 square metres and 110,000 square metres of usable floor area.

The Soviet government held an architectural competition in 1934 for this administrative complex that attracted numerous proposals from leading architects. The project emerged as part of Moscow's modernization efforts during a period of rapid industrial growth in the Soviet Union.

The 1934 contest drew 120 entries, split between classical and avant-garde approaches. F. Karyakin's proposal packed six half-scale replicas of Boris Iofan's Palace of Soviets tower onto the Red Square facade. Some historians read the competition as a way to steer Stalinist architecture's direction or to sideline avant-garde architects rather than a real construction plan.

The intended site in Kitai-gorod and Zaryadye is now occupied by the GUM department store, the Rossiya Hotel site (cleared in 2006–2007), and Zaryadye Park. No trace of the Narkomtiazhprom remains; the 1934 and 1936 competition drawings are held in Russian architectural archives and can be consulted by researchers.

The design proposed connecting three towers with distinctly different floor plans: a quadrangle, a cylinder, and a hexagon, linked by elevated walkways. This unusual approach made it one of the most experimental tower concepts of its era.