David O'Brien

In September 2015, O'Brien was pre-selected by the National Party to contest the Polwarth state by-election following the resignation of the Liberal MP Terry Mulder. He was unsuccessful.

O'Brien was the Deputy Leader of the Nationals in the Legislative Council, but lost his seat in 2014 to James Purcell, representing Vote 1 Local Jobs. Whilst in Parliament he served on the Scrutiny of Acts and Regulations Committee, the Public Accounts and Estimates Committee, the Family and Community Development Committee, the Accountability and Oversight Committee, the Legal and Social Issues Committee, the House Committee and in 2014 as chair of the Rural and Regional Committee. Prior to the 2014 election, O'Brien considered switching to the safe lower house seat of Lowan, which commentators views as a logical move to safeguard O'Brien's parliamentary career and position himself as a future party leader. However, it is believed that the move was blocked by then-deputy leader Peter Walsh, who preferred to see the seat filled by a woman.

O'Brien was elected to the Victorian Legislative Council as a Member for the Western Victoria Region at the 2010 election. Previously he was the unsuccessful Nationals candidate for the seat of South West Coast at the 2006 election. He is the only National to be elected to the upper house from Western Victoria since the changeover to the regional proportional representation system at the 2006 election.

David Roland Joseph O'Brien (born 2 September 1970) is an Australian politician who represented the National Party in the Victorian Legislative Council.