About Mark O'Brien


Mark is listed in Chambers Asia Pacific, the Clients Guide, 2015 as a Band 1, Media lawyer, and is cited as being "second to none and has the widest experience in Australia"


Mark O’Brien brings more than 40 years experience in managing cases spanning commercial law, taxation, intellectual property, media and defamation and representation in ICAC and negotiations with ASIC.  He has worked for public corporations, non-executive directors, major media organizations, artists, small and medium-sized businesses, politicians and community organizations. 

Mark has headed the litigation group in several top Australian legal firms, has conducted many high-profile cases in the Federal Court and Australian Supreme Court and has worked with leading US, UK and European law firms.  He has been consistently acknowledged and recognized as one of Australia’s leading lawyers in independent peer review publications. 

In his chambers legal practice Mark represents both individual and corporate clients in defamation, commercial litigation, public authority investigations and white-collar prosecutions.  

In his legal consultancy role, Mark is able to assist at any stage of a case, from providing initial assessment of a prospective matter, to advising clients on the case plans developed by their internal or external legal teams, carrying out strategic interventions when a client has concerns about how their case is being conducted, and resolving disputed issues on behalf of clients with their legal or financial representatives.   

He has a particular interest in assisting clients to negotiate fixed fees for a case, eliminating risky time-based costings wherever possible.