He represents domestic and international clients in a wide range of litigation matters, including commercial disputes, employment related disputes, intellectual property related disputes, administrative disputes, enforcement and set-aside lawsuits, as well as criminal proceedings in relation to white-collar crimes at all levels of Turkish courts.

With significant experience of almost 25 years in international arbitration, he has been extensively involved in numerous ICC, DIS, SAC, LCIA, DIAC, LME, ITOTAM and ISTAC arbitration proceedings, as well as various ad hoc arbitrations under the UNCITRAL Arbitration Rules, where he has served as counsel, arbitrator (presiding arbitrator, sole arbitrator or co-arbitrator) or expert witness. Okan has been heavily involved in arbitration proceedings concerning major infrastructure projects and has successfully represented several international clients as well as local entities in arbitration proceedings concerning disputes arising from build-operate-transfer (BOT) model investments, share purchase agreements, shareholders agreements, sales agreements, EPC contracts and licensing contracts. He is also a Fellow of the Chartered Institute of Arbitrators (FCIArb) and the Swiss Arbitration Ambassador to Türkiye as well as Board Member of the Swiss Arbitration Association (ASA). In 2024, he became a member of the International Bar Association’s (IBA) Arbitration Committee and the co-chair of Enforcement & Recognition Sub-Committee.

Okan is recognised as a Leading Partner by The Legal 500 in its Dispute Resolution, Compliance and Energy categories as well as ranked in “Band 1” in Litigation and “Band 2” in Arbitration listings by Chambers Global and Chambers Europe. Chambers Europe also ranks him in its Projects & Energy category. Lexology recognises Okan Demirkan as a “Global Elite Thought Leader” in the field of Energy since 2020. In addition, Lexology and GAR recognize him as a “Thought Leader” in the field of Arbitration and Lexology also lists him in the fields of Commercial Litigation and Asset Recovery. The IFLR1000 also names him as a Highly Regarded Lawyer. In 2025, Benchmark Litigation has recognized him as “Türkiye Litigator of the Year”.