Konstantin Yuryevich Nikolaev (also transliterated as Nikolayev) (Russian: Константин Юрьевич Николаев; born March 5, 1971, in Dniepropetrovsk, Ukraine SSR) is a Russian billionaire and businessman who is a financial supporter of Maria Butina,[2][3][4] a co-owner of the Tula Cartridge Plant that supplies very large amounts of ammunition to Russian forces during Russia-Ukraine War, American Ethane, N-Trans and Globaltrans, the largest private rail operator in Russia, CIS, and the Baltic states.

[8][9] Through Igor Levitin, Alexey Mordashov, Arkady Rotenberg, Gennady Timchenko, and Alexander Voloshin, Nikolaev is a partner and close associate of numerous persons in Vladimir Putin's inner circle.

[9] In April 2015, Marc O'Polo investments sold its stake in Mostotrest to NPF Blagosostoyanie (Russian: НПФ "Благосостояние").

[9][28] Sergey Shishkarev's Delo Group purchased the stakes of Nikolaev, Mishin, and Filatov in Global Ports which includes the management of the ports at the First Container Terminal, Petrolesport, Ust-Luga Container Terminal, and the Moby Dick in northwestern Russia; Eastern Stevedoring Company in the Far East; and two in Finland: the Multi-Link Helsinki and the Multi-Link Kotka.

[36] During the summer of 2013 as an investor, Nikolaev through his managers actively discussed with Alexander Tarasov, who is a representative of the Cyclone Institute and the son of Viktor Tarasov who is the owner of the Cyclone Institute,[c] and the mediator Alexey Beseda, who is the son of Sergey Beseda,[38] about the production of matrices for thermal imagers and "photoelectronic devices".

[39][40] In January 2017, Konstantin Nikolaev, his wife Svetlana Nikolaeva and Maria Butina attended the inauguration of Donald Trump as President of the United States.

[36][39][31][7][62] Since 2010, he and the Rotenberg family co-own the armaments firm Promtekhnologiya LLC (Russian: ООО «Промтехнология»), which produces Orsis sniper rifles.

[42] In 2015, Maria Butina gave numerous Americans, some of which are associated with the National Rifle Association of America (NRA) including Joe Gregory, David Keene, David Alexander Clark Jr. and Pete Brownell, tours of the Promtekhnologii plant in Podolsk which manufactures ORSIS rifles as well as access to Dmitry Rogozin.

[42] His son Andrey Nikolaev (Russian: Андрей Константинович Николаев) lived in the United States as a student at Columbia University in New York City during 2016 and was a volunteer at Donald Trump's headquarters during his Presidential Campaign in 2016.