[2] He joined the Australian Broadcasting Corporation in 1995, initially based at the local ABC station in Rockhampton, Queensland before moving to Brisbane where he worked as a reporter and presenter.
[2] During the Australian Marriage Law Postal Survey in 2017, O'Brien's questioning of the Australian Christian Lobby's Lyle Shelton was criticised by commentators Tom Switzer and Andrew Bolt who both believed O'Brien had suggested same sex marriage opponents had no right to support gay athletes such as Ian Thorpe.
O'Brien grew up in Innisfail, Queensland after his parents moved from New South Wales with their four young children around 1970.
[8] In 1999, he performed as a back-up dancer for Dannii Minogue at the Sydney Gay and Lesbian Mardi Gras.
[9] O'Brien was a brother-in-law to Australian rugby league player Peter Jackson, who died from a heroin overdose in 1997.