Oleh Marchenko chairs Disputes at Marchenko Partners. He is one of Ukraine’s leading practitioners in arbitration, cross-border litigation, investor-state disputes, and public international law.

Oleh focuses on commercial and other disputes involving high-stake public policy interests. His cases regularly make headlines in national and international media. Oleh acts for global clients, such as Gilead, Philip Morris International, MHP SE, US Ex-Im Bank, Holcim, and Microsoft.

Best Lawyers (2017–2021 editions) ranked Oleh as one of the top practitioners in arbitration, mediation and litigation in Ukraine. According to The Legal 500 EMEA, Who’s Who Legal, Benchmark Litigation, Oleh is described as ‘a first-class professional’ having ‘a superb reputation’, ‘a star individual’, ‘an exceptionally talented lawyer’, ‘a top-notch lawyer’, possessing ‘impressive and profound expertise’, doing ‘superior work’, ‘open-minded and creative’, and having ‘a talent to explain and argue complex legal issues in a simple and convincing manner’.