Konstantin Yuryevich Nikolaev (Russian: Константин Юрьевич Николаев; born March 5, 1971 in Dniepropetrovsk) is a billionaire Russian businessman who is a co-owner of N-Trans and Globaltrans, the largest private rail operator in Russia, CIS, and the Baltic states. He is a major investor in American Ethane and serves on its board. Late July 2018, his net worth was estimated at $1.2 billion. He allegedly is a financial supporter of Maria Butina. Through Igor Levitin, Alexey Mordashov, Arkady Rotenberg, Gennady Timchenko, and Alexander Voloshin, Konstantin Nikolaev is a partner and close associate of numerous persons in Vladimir Putin's inner circle.