Michael O'Brien

Michael Anthony O'Brien (born 5 August 1971) is an Australian politician. He has been a Liberal Party member of the Victorian Legislative Assembly since 2006, representing the electorate of Malvern and served as the leader of the party and opposition leader from December 2018 to September 2021. He served as the Shadow Attorney-General of Victoria until 11 October 2025.

O'Brien served as Minister for Gaming, Minister for Consumer Affairs and Minister for Energy and Resources in the Baillieu government from 2010 to 2013, and was promoted to Treasurer in the 2013–2014 Napthine government. Following the defeat of the Napthine government at the 2014 state election, O'Brien contested the leadership of the Liberal Party, but was defeated by Matthew Guy. Guy resigned the party leadership following the party's defeat at the 2018 state election. Subsequently, on 6 December 2018, O'Brien was elected leader of the Liberal Party and became opposition leader.

Education

O'Brien underwent secondary education at Marcellin College before completing a Bachelor of Laws (Honours) and a Bachelor of Commerce from the University of Melbourne. He worked as a barrister at the Victorian Bar practising in the fields of trade practices and commercial law. With co-author Jamie Richardson, O'Brien won the Law Institute of Victoria's Rogers Legal Writing Award in 2006. Matthew Guy made O'Brien shadow treasurer in opposition.

Leader of the Opposition 2018–2021 On 6 December 2018, O'Brien was elected the leader of the Liberal party after Guy resigned following the 2018 state election defeat. He then arranged his Shadow Cabinet, with Cindy McLeish his deputy.

O'Brien regularly attacked the government on its COVID-19 lockdown policies, more specifically contact tracing and hotel quarantine failures, even raising a motion of no confidence in the government. Despite this negative polling, O'Brien stated that he was confident of remaining leader of the Victorian Liberals in 2022.

Post-leadership 2021–present On 7 September 2021, O'Brien was replaced by Guy as party leader and opposition leader in a leadership spill. Initially, he declined to be in Guy's shadow cabinet, but in February 2022, he was appointed as shadow attorney-general, a role which he has held to the 11 October 2025.

O’Brien was re-elected to his seat of Malvern at the 2022 election, with a primary vote of 52.8%.

On 9 September 2025, O'Brien announced he will retire from Parliament at the 2026 Victorian state election, making him become replaced as Shadow Attorney-General by James Newbury on 11 October 2025.

Political views O'Brien is widely considered a moderate within the Liberal Party, and is conscious about climate change.

Personal life Michael O'Brien lives in his Malvern electorate with his wife and two children.

O'Brien supports the Carlton Football Club in the Australian Football League, plays golf, and co-founded the Spring Street Blues, a Victorian MP supporter group for Carlton.