Horst Köhler (German: [ˈhɔʁst ˈkøːlɐ] (listen); born 22 February 1943) is a German politician who served as President of Germany from 2004 to 2010. As the candidate of the two Christian Democratic sister parties, the CDU (of which he is a member) and the CSU, as well as the liberal FDP, Köhler was elected to his first five-year term by the Federal Convention on 23 May 2004 and was subsequently inaugurated on 1 July 2004. He was reelected to a second term on 23 May 2009. Just a year later, on 31 May 2010, he resigned from his office in a controversy over a comment on the role of the German Bundeswehr in light of a visit to the troops in Afghanistan. During his tenure as president, whose office is mostly concerned with ceremonial matters, Köhler was a highly popular politician, with approval rates above those of both Chancellor Gerhard Schröder and later Chancellor Angela Merkel.

Köhler is an economist by profession. Prior to his election as president, Köhler had a distinguished career in politics and the civil service and as a banking executive. He was president of the European Bank for Reconstruction and Development from 1998 to 2000 and head of the International Monetary Fund (IMF) from 2000 to 2004. From 2012 to 2013, Köhler served on the UN Secretary-General's High-level Panel on the Post-2015 Development Agenda.