Carl Wilhelm Kaisen (22 May 1887 – 19 December 1979) was a German politician from the Social Democratic Party of Germany (SPD) who served as the 2nd President of the Senate and Mayor of Bremen from 1945 to 1965.

On 1 August 1945, the US military government made Kaisen mayor of Bremen.

Supported by the Liberals as well as the Communists he tried to re-establish the political and economical structures of the Weimar Republic.

His support for the decision to position Germany within NATO led to a break with SPD chairman Kurt Schumacher.

Although not well known in the rest of Germany, Wilhelm Kaisen is held in high regard in Bremen and Bremerhaven.