Kerry Williams Kelso O'Brien (born 19 July 1951), is an Australian former politician.

He was a research officer and elected official with the Federated Miscellaneous Workers' Union 1974–92, and Tasmanian Branch Secretary of the Australian Liquor, Hospitality and Miscellaneous Workers' Union 1992–96.

He was appointed Shadow Minister for Transport in June 2005.

[citation needed] From December 2007 to September 2010, he held the position of Chief Government Whip in the Senate.

[3] On 9 April 2010, he lost Labor preselection for the 2010 Australian federal election.