Stephan Weil is a German politician and the leader of the Social Democratic Party in Lower Saxony. On 20 January 2013, the SPD and the Green party won the 2013 Lower Saxony state election by one seat. On 19 February 2013, he was elected Minister President of Lower Saxony with the votes of SPD and Alliance '90/The Greens. From 1 November 2013 until 31 October 2014 he was President of the Bundesrat and ex officio deputy to the President of Germany. In November 2017, he was again elected Minister President with the votes of SPD and CDU.

The 2013 Lower Saxony state election was held on 20 January 2013 to elect the members of the 17th Landtag of Lower Saxony. The incumbent coalition government of the Christian Democratic Union (CDU) and Free Democratic Party (FDP) led by Minister-President David McAllister was defeated. The Social Democratic Party (SPD) formed a government with The Greens which held a slim, one-seat majority. Stephan Weil was subsequently elected Minister-President.