Friedrich Otto Hörsing (18 July 1874 – 16 August 1937) was a German Social Democratic politician who served as chairman of the Reichsbanner Schwarz-Rot-Gold from its foundation in 1924 until 1931.

Hörsing was born in Groß Schilleningken near Memel, East Prussia (today Šilininkai, Lithuania), and was trained to work as a blacksmith in his youth.

In 1919 and 1920 Hörsing was the Reichs- und Staatskommissar for Silesia and Posen and the Oberpräsident of the Province of Saxony in 1920 until 1927.

Hörsing represented the Province of Saxony in the Reichsrat in 1922–1930 and was a co-founder and the first Chairman of the Reichsbanner Schwarz-Rot-Gold (1924–32), which he described as a 'non-partisan protection organization of the Republic and democracy in the fight against the swastika and the soviet star'.

[3] In 1932, Hörsing founded the Sozial-Republikanische Partei Deutschlands after he was expelled from the SPD and the Reichsbanner.