Boris Christoff (18 May 1914 – 28 June 1993) was a Bulgarian singer. He sang in the bass range. Critics thought him to be one of the great acting singers of the 20th century. He sang some 40 roles. His most famous role was Boris Godunov. He also received kudos for his Philip II in Verdi's "Don Carlo", and for his Mephistopheles in Gounod's "Faust". He sang several Wagnerian roles. These included Hagen in "Gotterdammerung" and King Mark in "Tristan und Isolde".