Charles Joseph Vopicka (born as Karel Boromejský Josef Vopička) (November 3, 1857 – September 4, 1935) was an American diplomat of Czech origin who served as United States Minister to Bulgaria, Romania, and Serbia.

He was born as Karel Boromejský Josef Vopička on 3 November 1857 at Dolní Hbity house 2, Příbram, Bohemia, Austrian Empire and baptized Catholic the next day.

[2] On September 11, 1913, President Woodrow Wilson[4] appointed Vopicka as United States Envoy Extraordinary and Minister Plenipotentiary to Romania, Serbia and Bulgaria.

Added to the delicate situation which was created by the daily snapping of diplomatic threads, there was imposed upon him the extra hazardous task of acting as Chairman of the International Commission in Serbia, where he was also representing the German and Austro-Hungarian interests.

After the termination of hostilities and the consequent resumption of international amenities, Minister Vopicka conducted parleys for the various powers and has notably assisted in the task of building order out of chaos and destruction.