Karl Joseph Hieronymus Windischmann (25 August 1775, in Mainz – 23 April 1839, in Bonn) was a German philosopher and anthropologist.

After a year at Vienna he settled in 1797 as a practising physician at Mainz, where he also gave medical lectures; in 1801 the Elector of Mainz, Friedrich Karl Joseph von Erthal, summoned him to Aschaffenburg as court physician.

He took an active part against the ideas of George Hermes in the University of Bonn, and when the investigation of Hermesianism began at Rome he was one of the German scholars directed to draw up opinions.

But the work was not finished; of its four volumes (Bonn, 1827–1834) only the first, dealing with China and Japan were printed.

[3] His son was the orientalist and theologian Friedrich Heinrich Hugo Windischmann.