Sp.Vg. Blau-Weiß 1890 Berlin, generally referred to as Blau-Weiß 90, was a German association football club based in the Mariendorf district of Berlin. The club was formed on 27 July 1927 out of the merger of Berliner FC Vorwärts 1890 (November 1890), German championship runner-up of 1921, and Berliner Thor- und Fussball Club Union 1892 (BTuFC Union, June 1892), German champions of 1905.