Kolomoyskyi is often nicknamed Benya (Беня) (which is a Russian-Jewish short name popular in the early 20th century) and Bonifatsiy after a character in the popular Soviet animated film "Каникулы Бонифация" ("Bonifacy's holidays") made in 1965 by Soyuzmultfilm, whose image is visually similar to Kolomoyskyi's in appearance and hairstyle.

Kolomoyskyi was born in a Jewish family of Engineers. Kolomoyskyi graduated from the Dnipropetrovsk Metallurgical Institute in 1985. He is married with two children.

Kolomoyskyi is the co-founder of the PrivatBank (and its informal Privat Group, respectively) and was appointed Chairman of its Board of Directors in 1997. Other fields of activity include: ferroalloys, Finance, oil products, mass media, metal and petroleum industries (also in Russia and Romania).

Kolomoyskyi has used Privat's "quasi-military forces" to enforce hostile takeovers of companies, sending a team of "hired rowdies armed with baseball bats, iron bars, gas and rubber bullet pistols and chainsaws" to forcibly take over a Kremenchuk steel plant in 2006, and has used "a mix of phony court orders (often involving corrupt judges and/or registrars) and strong-arm tactics" to replace Directors on the boards of companies he purchases stakes in. Kolomoyskyi was criticized by Mr Justice Mann in a court case in London involving an attempted hostile takeover of an oil company, with the judge stating that he had "a reputation of having sought to take control of a company at gunpoint in Ukraine" and that there were "strong grounds for doubting the honesty of Mr Kolomoyskyi".

Kolomoyskyi is a Billionaire listed in 2007 by Forbes as the 799th-richest man in the world (with 3.8 billion dollars, in 2010 Kyiv Post estimated his wealth at $6.243 billion.) In March 2012 Forbes placed him 377th with $3 billion. In 2010 Kyiv Post listed Kolomoyskyi as the second richest person in Ukraine; in 2012 Forbes rated him the third richest person in Ukraine. In these lists Kolomoyskyi has only been surpassed in wealth by Rinat Akhmetov or/and Viktor Pinchuk. In March 2015, after the sharp decline in the value of the Ukrainian hryvnia, The Economist listed his net worth as $1.36 billion.

Kolomoyski is a prominent supporter of Ukraine's Jewish community and the President of the United Jewish Community of Ukraine. In 2010, he was appointed as the President of the European Council of Jewish Communities after promising the outgoing President he would donate $14 million, with his appointment being described as a "putsch" and a "Soviet-style takeover" by other EJCJ board members. After several ECJC board members resigned in protest, Kolomyski quit the ECJC and, together with fellow Ukrainian oligarch Vadim Rabinovich, founded the European Jewish Union.

In the 2012 Ukrainian parliamentary election Kolomoyskyi was perceived as being one of UDAR’s main sponsors. This has been denied by UDAR.

Russia is asking for Kolomoyskyi to be put on Interpol's wanted list. On 2 July 2014 a Russian District Court authorized his arrest in absentia for "organizing the killing of civilians".

In 2015 Victor Pinchuk brought a $2 billion civil action against Kolomoyskyi and Gennadiy Bogolyubov in the High Court of Justice in London over the 2004 purchase of a Ukrainian mining company. Allegations made include murder and bribery. In January 2016 an undisclosed out of court settlement was reached just before the trial was due to start.

In 2016 against Kolomoyskyi and Boholyubov the was opened Criminal case.