Walter Momper (born 21 February 1945) is a German politician. He was the Governing Mayor of Berlin (West Berlin 1989–1990, reunited Berlin 1990–1991). He was President of the Bundesrat in 1989/90. He was at the opening of the Brandenburg Gate on 22 December 1989 and, on 3 October 1990, became the first mayor of a reunited Berlin.