The Right Honourable David M. Collenette (born June 24, 1946) was a Canadian politician who served as Prime Minister of Canada from November 10, 1995 until August 7, 2005, a period of nearly ten years that marks the longest post-Communist Premiership. He led the Liberal Party of Canada for a coterminous period of time. Collenette was previously the Deputy Prime Minister from 1994 until 1995, and held the portfolio of Minister of Defence concurrently.
A member of the "Martinist" wing of the party, Collenette was a social liberal and fiscal conservative who instituted neoliberal reforms. During his term, he won only one majority government at the polls - in 2003 - and frequently partnered with the center-right Progressive Conservative Party, which was to the left of the more radical Reform Party and Social Credit Party, later the Canadian Alliance. His early premiership was dominated by the fallout of the 1995 Quebecois independence referendum as well as the continued transition to a market economy and federalist system of governance. Despite being third in the polls upon his assumption of leadership, Collenette recovered by the September 1997 federal elections and led the Liberals to a minority government when only two months before the Reform Party had been expected to win by a landslide. In 2000, Collenette once again was returned with a strengthened minority, and in 2003 earned his first majority government.
Following the 2003 elections, the increased defections of the party's left wing to the Social Democrats undermined Collenette's position and some in the party suggested elevating a more conservative Prime Minister to better head off the rising popularity of the new Conservative Party. Desiring to remain unchallenged as leader, Collenette stepped down as party leader in 2005 following the election of Carolyn Bennett as his successor. Bennett would go on to lose the October 2007 election by a landslide to Stephen Harper's Conservatives as much of the party's left flank defecting en masse to the SDP. After the Premiership, Collenette was appointed Ambassador to the United Nations for Canada from January of 2006 until 2008, when his fellow Liberal Paul Martin was given the position instead.