Simon McDonnell O'Brien (born 16 May 1960) is an Australian politician who was a Liberal Party member of the Legislative Council of Western Australia from 1997 to 2021, representing South Metropolitan Region.
His father, who died when his son was eleven, was a Labor Party member of parliament in the 1950s.
After leaving school, he twice began officer training with the Australian Army, but had to withdraw because of injury.
[2] O'Brien first attempted to enter parliament at the 1989 state election, when he unsuccessfully contested the Legislative Assembly seat of Cockburn (losing to Labor's Bill Thomas).
He was not retained in the ministry after the 2013 election, but was instead made deputy chairman of committees in the Legislative Council (a position which he had earlier held from 2001 to 2008).