Sydney media and commercial lawyer
Mark Geoffrey O'Brien is a media and commercial lawyer with more than 40 years' experience, and one of Australia's best known defamation lawyers. He founded Mark O'Brien Legal in Sydney in 2014.
Profile
Mark has headed the litigation group in several national Australian law firms and has supervised major litigation in the Federal Court and the Supreme Courts of Australia. He has worked alongside leading US, UK and European law firms.
He acts for public corporations, chief executives, directors, major media organisations, artists, businesses, politicians and community organisations, and is regarded by his media clients as a trusted advisor for prompt, strategic advice.
Expertise
Advising media companies, public figures and businesses on defamation, broadcasting, contempt and copyright.
Strategic advice for individuals and organisations when their reputation is in issue.
Litigation in the Federal Court and the Supreme Courts of Australia, and international commercial disputes.
Representing private and corporate clients in investigations and hearings, and in dealings with government and statutory authorities.
Acting for defendants in ASIC prosecutions, including insider trading and money laundering matters.
Trade mark and copyright matters, including Federal Court proceedings.
Recognition
Band 1, Media
One of the nation's most feared defamation lawyers
One of the country's top defamation lawyers
Feared defamation lawyer
Insights
When a damaging story is coming, or has just broken, the first hours count. Legal strategy and communications need to work together from the start.
Read the articleSince 2021, Australian publishers have had a defence for responsible public interest journalism. It is valuable, but it is not a licence to publish anything that seems newsworthy.
Read the articleA false post, review or video can spread quickly. The first steps you take will shape your options, so it pays to be calm and methodical.
Read the articleThe serious harm threshold, concerns notices and the single publication rule have changed how defamation disputes begin. Here is what they mean in practice.
Read the articleMark O'Brien Legal
Confidential advice on defamation, media and commercial disputes, through Mark O'Brien Legal in Sydney.