Matthew John (Matt) Birney (born 10 June 1969) is an Australian politician. He was a Liberal member of the Western Australian Legislative Assembly from 2001 to 2008, serving as Leader of the Opposition from 2005 to 2006.
Birney was born in Sydney but comes from a family long established on the Western Australian goldfields, and has lived in the regional city of Kalgoorlie since childhood. His father, Jack Birney, was a Liberal member of the Australian House of Representatives from 1975 until his defeat in 1983.
The younger Birney was educated at North Kalgoorlie Primary and Eastern Goldfields Senior High School. He was a small business proprietor and a board member of the Kalgoorlie-Boulder Chamber of Commerce and Industry, before being elected to the Western Australian Legislative Assembly for the seat of Kalgoorlie in February 2001, defeating Labor incumbent Megan Anwyl. The seat had long been a Labor stronghold; Labor had held it without interruption since 1923 and for all but seven years since its creation in 1901. However, Anwyl only led Birney by eight votes on the first count. Birney defeated Anwyl when a One Nation candidate's preferences flowed overwhelmingly to him. He was the first Liberal ever to win Kalgoorlie, and only the third non-Labor member in the seat's 100-year history. He was also the only Liberal challenger to unseat a Labor incumbent in an election which saw Labor elected to a strong majority government.
Birney was Shadow Minister for Youth and the Goldfields-Esperance region from 2001 to 2002, Shadow Minister for Police, Goldfields-Esperance and Communication Services from 2002 to 2004 and Shadow Minister for Police, Commerce, Communications and Goldfields-Esperance from 2004 to 2005.
Despite his relative lack of experience, Birney was widely seen as one of the Liberal Party's better performers in Opposition during the 2001 to 2005 parliament. After the Liberal Party under Colin Barnett was heavily defeated at the 2005 elections by the Labor government of Geoff Gallop, Barnett returned to the backbench. Birney was elected unopposed as party leader. He had retained Kalgoorlie with a healthy swing of eight percent, making Kalgoorlie a safe Liberal seat.
After becoming leader, Birney came under consistent criticism from both inside and outside his party. A number of public gaffes, including saying that the Pope had a wife and taking his girlfriend on a tax-payer funded tour of Europe, reduced his effectiveness as Opposition Leader. Within the party he was criticised for his lack of inclusiveness in policy formation. These problems led Barnett's former deputy leader, Paul Omodei, to challenge Birney for the leadership. Omodei defeated Birney in a party room ballot held on 24 March 2006. Omodei stated he would consider offering Birney a position on the Liberal front bench, but Birney remained on the back bench thereafter.
Birney's demise as WA Liberal leader was later echoed by that of South Australian Liberal leader Iain Evans a year later in 2007. Both Birney and Evans became their party's leaders following its defeat in the respective state elections only to be dumped a year later in a leadership coup.
On 3 January 2008, Birney announced that he would be quitting politics for the corporate world, and duly retired at the 2008 state election.
On 24 August 2014, The Sunday Times reported that Birney was considering a return to state politics, quoting him as saying that he had "unfinished business". He said he would not challenge a sitting member for pre-selection.