Peter Howard Costello is an Australian businessman, lawyer and former politician who served as the treasurer of Australia in government of John Howard from 1996 to 2007. He is the longest-serving treasurer in Australia's history. Costello was a member of parliament (MP) of the Australian House of Representatives from 1990 to 2009, representing the Division of Higgins. He also served as the Deputy Leader of the Liberal Party from 1994 to 2007.

The treasurer of Australia, also known as the Federal treasurer or simply the treasurer, is the minister of state of the Commonwealth of Australia charged with overseeing government revenue collection, federal expenditure and economic policy as the head of the Department of the Treasury. The current treasurer is Jim Chalmers, who was selected by Prime Minister Anthony Albanese in May 2022 following the 2022 Australian federal election.