John N. Kleisarhakis is a graduate of the Law School of Aristotle University of Thessaloniki. (2005). He has been a member of the Thessaloniki Bar Association since 2007 and has been practicing law since.

He holds a Postgraduate Degree in Criminal Law from the Law School of the Aristotle University of Thessaloniki (2007) and a doctoral candidate of the Civil Procedure of the Department of Law of the Aristotle University of Thessaloniki (2016) with a thesis on "Conservative seizure in the hands of a third party".

His professional work concerns the handling of civil and criminal law cases at the judicial level and in the provision of legal advice and services to businesses.

His main areas of specialization are Criminal Law (Financial Criminal Law, Tax Criminal Law, Market Law, Health Law, Urban Law), Hotel Law, Medical Law (Criminal - Civil), Commercial Law (Contract – Securities), Labor Law, Automotive Legal Disputes, Lease Law.

In his postgraduate studies in Criminal Law, he has carried out many studies, such as: "The principle of non reformatio in pejus in the Greek penal procedure," Theoretical issues of the crime of fraud Article 386 P.C and Computer Fraud Article 386a "Medical Liability, Medical Negligence", "Substantive and Procedural Issues of Law 1608/1950 on Abusers of the Public Sector", "Issues of Proof in Criminal Proceedings", "Corruption in the Public Services and the Political Life of Greece", "The Financial crime through textbooks and conceptual identification".

He is Fluent in English, French and German.