Igor Valeryevich Kolomoisky, or Ihor Kolomoysky (born February 13, 1963), is a Ukrainian-Cypriot-Israeli business oligarch of Jewish descent and the former Governor of Dnepropetrovsk Oblast.

A multibillionaire, Kolomoisky is rated as the second or third richest person in Ukraine (after Rinat Akhmetov and/or Viktor Pinchuk) since 2006, and 377th richest person in the world by the Forbes (as of 2011). In March 2015 The Economist listed his net worth as $1.36 billion. Kolomoisky is the leading partner of the Privat Group and a de facto chairman of the FC Dnipro Dnipropetrovsk.

Igor Kolomoisky and Gennady Bogolyubov founded PrivatBank with $1 million in capital in the early 1990s. Over the years it grew to be a key bank in Ukraine, handling more than a third of private deposits and serving approximately half of the country's entire population. Then in 2016, Ukraine's government nationalized the bank. Their Privat Group still has other assets including gas stations and oil refiner, among others. He was forced to step down as governor of the Dnipropetrovsk region in March 2015. The partners also settled a lawsuit with billionaire Viktor Pinchuk who had sued them for damages for unfulfilled pledges on mining investments. He is a generous donor to jewish causes.