About Onno

Onno Hennis has been a lawyer since 2009 and joined the AMS Advocaten team in 2015. Onno studied law (with honours) and European Studies at the University of Amsterdam and the Humboldt University in Berlin. Following his studies, Onno worked at De Brauw Blackstone Westbroek, where he successively dealt with mergers and acquisitions, and general procedural law.


At AMS Advocaten, Onno focuses on advising and litigating in commercial and corporate disputes. He deals with issues that arise within companies (such as impasses in general meetings of shareholders and directors’ and officers’ liability), as well as disputes between companies and external parties (such as former trading and investment partners, suppliers and customers).

Lecturer at the University of Amsterdam

Onno is a lecturer at the University of Amsterdam, where he lectures and guides students in their participation in international advocacy competitions. He gives lectures for the master’s course “International Commercial Arbitration’ and assesses bachelor’s essays and master’s theses.

German Desk

Onno speaks fluent English and German. Thanks to his experience – including at Allen&Overy in Frankfurt am Main – he is in an excellent position to advise clients who have activities in Germany. Onno is responsible for the German Desk of AMS Advocaten.

Expert at BusinessInsider.nl and BNR

In addition to his daily law practice, Onno is also an expert attached to the Dutch business news website BusinessInsider.nl. In the radio programme BNR Juridische zaken, Onno regularly presents his views on current legal themes.


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