The Federation Tower (Russian: Башня Федерация, romanized: Bashnya Federatsiya) is a complex of two skyscrapers built on the 13th lot of the Moscow International Business Center in Moscow, Russia. The two skyscrapers are named Tower East or Vostok (Russian: Восток; literally means "East") and Tower West or Zapad (Russian: Запад; literally means "West").

The supertall skyscraper Tower East (Vostok) is currently the second-tallest skyscraper in Europe and Russia after the Lakhta Center, the tallest building in Moscow, and the 55th-tallest building in the world. Zapad is a shorter skyscraper than Vostok and is the eleventh-tallest building in Russia, and the 22nd-tallest building in Europe. The complex stands on the 13th lot, which has an area of 439,154 square meters.

The project was conceived by German-Russian engineer Sergei Tchoban and German professor and engineer Peter Schweger. The complex was designed by architecture companies nps+partner and Schweger Associated Architects. The complex started construction in 2005, with Zapad completed first in 2008 with a height of 242 meters (794 feet). As a result of the Great Recession, construction of the complex stopped until August 2011, and Vostok was completed on 7 December 2017 with a height of 374 meters (1,227 feet). In late 2014, Vostok surpassed the South Tower of OKO, which it is also part of the MIBC, as the tallest skyscraper of Russia and Europe. A spire was to be also built which would have extended the complex's height to 450 meters (1,480 feet) as well as provided an observation deck but it was never completed and was dismantled afterward.

The complex is owned by the AEON Corporation, a Russian private international investment group. The complex consists of two towers built on one podium. Tower East is a 97-story structure and Tower West is a 63-story structure. The complex is bounded by a rectangle of 3 alleys & a driveway. All three alleyways are named Krasnopresnenskaya Embankment, but the driveway on its east side is named 3rd Main Street. On 30 July 2023, across the alley from the back entrance, on the first floor, an aircraft (a Ukrainian drone) crashed into Rosbank (whose address is 1st Krasnogvardeisky Direction 19) & exploded, causing a small amount of damage to its facade.

The higher tower of the complex located in the eastern part of lot number 13 was formerly known as Tower "A". But in November 2006, to avoid name competition with Naberezhnaya Tower, it was renamed Tower "Vostok (East)". Tower East is designed to have 95 above-ground and 3 underground floors, and 17 high-speed elevators will be installed there (JP. Kocher). According to the company Potok, which is the builder of the tower, it used grade B90 concrete which is twice as strong as regular concrete and will allow the skyscraper to withstand a direct hit of an aircraft. In early December 2009, the Potok Corporation management (ex-Mirax Group) announced that in the case of financial problems it could reduce the number of floors of Tower East from 95 to 64 floors. However, in March 2010, the company's management stated that Tower East would be completed according to the original project design.

The construction of this tower is the second stage of the entire complex construction, and during the construction of the first tower, "Zapad (West)", its design underwent some significant changes and became radically different from the original version. In the first place, the square footage of the floors changed, and visually the tower became thicker at the base to the extent that a part of the floors, starting with the 11th, protrude a little beyond the 13th lot borderline. The tower core was significantly revised, too, and now has a trapezoidal shape rather than hexagonal as in the earlier design. The load-bearing columns became twice as thick; therefore, the amount of concrete required for the construction of the columns increased 4 times, and, consequently, significantly increased the total mass of the building.

Construction started in 2005. During the construction of the foundation slab on 21–24 February 2007, a new record listed in the Guinness Book of Records was set: 14,000 cubic meters of concrete were placed then. Somewhat unusual in the construction process was that the first base plate was covered with the second base plate, which resulted in the complex losing one underground level and the construction delayed by at least five months. The extravagance of this decision lies in the fact that, judging by the photographs obtained from the site, the builders began active preparations for the construction of the first underground floor, but suddenly stopped working, dismantled the installed cranes, cut the reinforcement bars previously prepared for the columns and began to place reinforcement for the second base plate. That the construction organizers did not clearly comment on the reasons for this decision was also unusual. The tower was climbed solo by the Frenchman Alain Robert in September 2007.

In the process of further construction the pace of the tower erection changed over a fairly wide range: the underground and podium parts of the building were being built at an average rate of about two levels a month; after the podium was completed, the construction of standard floors went at a faster rate of four floors per month, while at the technical 33–34 levels of the building the construction of that floor was significantly suspended and lasted more than five months; one of the cranes was replaced with two more powerful ones, and a strong metal outrigger structure was formed, contributing to the greater rigidity of the building and its resistance to wind loads.