Katherine O’Byrne

Katie has experience in administrative and public law, regulatory proceedings, Royal Commissions, commercial disputes, class actions, discrimination, Charter and human rights cases, First Nations justice and children’s rights.

Katie acts in civil penalty proceedings and investigatory matters for regulators and other parties. Her recent advisory work has covered public governance structures, statutory powers and Charter compliance, including in the context of First Nations self-determination. She is currently briefed in a High Court appeal concerning procedural fairness and in major commercial class action litigation.

Before joining the Victorian Bar, Katie practised at Doughty Street Chambers in London (call 2013). She was counsel assisting the Independent Inquiry into Child Sexual Abuse, the Undercover Policing Inquiry and the Starmer Review of Sexual Abuse and Terrorism Cases in Northern Ireland.

For five years, Katie was counsel in the construction industry blacklisting litigation, involving hundreds of claimants against multiple major construction companies. She acted in group discrimination claims and cases concerning historical conduct of public authorities and the armed forces.

Katie was ranked in the leading legal directories in public law, public inquiries and civil liberties. She regularly acted for children in need in public law and human rights proceedings, represented clients before UN bodies and reported to the European Parliament on human rights issues.

From 2024–2025 Katie was Director of Legal at the Yoorrook Justice Commission, where she led the team supporting Commissioners to deliver Yoorrook’s reports and recommendations. Previously she was Deputy Director and counsel at Reprieve in London. She was an associate to the Hon Justice Hayne AC KC at the High Court of Australia, practised as a solicitor at Herbert Smith Freehills Kramer and holds an LLM from the University of Cambridge.

Katie read with Olaf Ciolek and her senior mentor is Kathleen Foley SC.