Otto Lohse (21 September 1859 – 5 May 1925) was a German conductor and composer.
Born in Dresden, Lohse studied with Hans Richter and Felix Draeseke at the Dresden Conservatory.
In 1882 he became conductor of two music societies in Riga, the Wagner Society and the Imperial Russian Music Society; seven year's later he became the first kapellmeister of the city's Stadttheater.
In September 1893 he became 2nd Kapellmeister at the Hamburg Stadttheater (Director and 1st Kapellmeister was Gustav Mahler); while in Hamburg he married in March 1895 soprano Katharina Klafsky.
During his two seasons (each 9 months) at the Hamburg Theater he conducted a total of 343 performances of 42 different operas .
The couple traveled to the United States in the summer of 1896 (breaching their contract with the Hamburg Opera) to join the Damrosch Opera Company, returning to Germany a year later.