Valdas Adamkus ([ˈvɐ̂ˑɫd̪ɐs ɐˈd̪ɐmˑkʊs]; born 3 November 1926) is a Lithuanian politician. He was the President of Lithuania from 1998 to 2003 and again from 2004 to 2009.

In Lithuania, the President's tenure lasts for five years; Adamkus' first term in office began on 26 February 1998 and ended on 28 February 2003, following his defeat by Rolandas Paksas in the next presidential election. Paksas was later impeached and removed from office by a parliamentary vote on 6 April 2004. Soon afterwards, when a new election was announced, Adamkus again ran for president and was re-elected. His approval ratings were high and he was regarded as a moral authority in the state. He was succeeded as the president on 12 July 2009 by Dalia Grybauskaitė.