Margarethe Siems (20 December 1879 – 13 April 1952) was a German operatic dramatic coloratura soprano and voice teacher.

After early training in piano and violin, she studied singing at the Dresden Conservatory with the Hungarian soprano, Aglaja Orgeni, who had herself been a pupil of Pauline Viardot and Mathilde Marchesi.

Siems' singing style (like that of her contemporaries Hermine Bosetti and Marie Gutheil-Schoder) was described by Michael Scott as "instrumental" rather than warmly emotional.

She made her final stage performance in 1925 as the Marschallin in Der Rosenkavalier in Breslau, but continued to sing in concerts, often with the German singer and composer, Georg Hartmann, a fellow resident of Bad Landeck, where she spent her retirement years.

Margarethe Siems – Königliche Sächsische Hofopernsängerin is a remastered selection of Siems' early recordings for G & T, Pathé, HMV and Parlophone, representing roles in a wide range of operas, including Aida, Der Rosenkavalier, Les Huguenots, Lucia di Lammermoor, La traviata, Dinorah, Lakmé, and Le nozze di Figaro.