Esther Silvana Koch-Mehrin (born 17 November 1970, in Wuppertal) is a German politician and former Member of the European Parliament with the Free Democratic Party of Germany. Until May 2011, she was Vice Chairwoman of the Alliance of Liberals and Democrats for Europe. She was a member of the European Parliament's Committee on Budgets. She also was a substitute member of the Committee on Budgetary Control and a member of the Delegation for relations with the Maghreb countries and the Arab Maghreb Union (including Libya). EU Representative to the Executive Board of W20, Member of the Advisory Board of the Council of Women World Leaders (CWWL), and Alumni of the Young Global Leaders Network of the World Economic Forum.
Like Karl-Theodor zu Guttenberg and Jorgo Chatzimarkakis's doctoral theses, Koch-Mehrin's 2001 thesis, titled 'Historical Currency Unions between Economy and Politics', was analysed by VroniPlag using a crowd-source effort, and she was accused of plagiarism. As a consequence of this, on 11 May 2011 she resigned as chairperson of the FDP in the European Parliament and as vice-president of the European Parliament, arguing that she wanted to end the strain the investigation put on her family.