Joanne Kate Swinson is a British former politician who was Leader of the Liberal Democrats from July to December 2019. She was the first woman and the youngest person to hold the position, as well as the shortest-serving holder of the post. Swinson was Member of Parliament (MP) for East Dunbartonshire from 2005 to 2015 and 2017 to 2019. In September 2020 Swinson became Director of Partners for a New Economy (P4NE).

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.