The 1999 Liberal Democrats leadership election was called following the resignation of Paddy Ashdown as Leader of the Liberal Democrats. There were five candidates and all members of the party were balloted using the Alternative Vote preference system. The election was won by Charles Kennedy, who served as leader until his resignation in 2006.

The Liberal Democrats are a political party in the United Kingdom. Party members elect the leader of the Liberal Democrats, the head and highest-ranking member of the party. Liberal Democrat members of Parliament also elect a deputy leader of the Parliamentary Party in the House of Commons, often colloquially referred to as the deputy leader. Under the federal constitution of the Liberal Democrats the leader is required to be a member of the House of Commons.