Rainer Michael Müller (born 9 December 1964) is a German politician of the Social Democratic Party (SPD) who served as Governing Mayor of Berlin from 2014 to 2021. He served as a member of the German Bundestag from 2021 to 2025, representing the Berlin-Charlottenburg-Wilmersdorf district.
He was also President of the Bundesrat from November 2017 until October 2018, which made him deputy to the President of Germany.
