Peter Howard Costello, AC (born 14 August 1957), is an Australian former politician and lawyer who served as the Treasurer in the Australian Howard Government from 1996 to 2007. He is the longest-serving Treasurer in Australia's history. Costello was a Member 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.