Karl Wilhelm Georg von Fritsch (11 November 1838, in Weimar – 9 January 1906) was a German geologist and paleontologist.
He studied forestry at the academy in Eisenach, followed by studies in natural sciences at the University of Göttingen, where he obtained his degree in 1862. Following graduation, he embarked on a scientific journey to Madeira and the Canary Islands. In 1863 he received his habilitation at Zurich, working as a lecturer at the "Polytechnikum". While in Zurich, he produced an accurate geological map of the Saint-Gotthard Massif. In 1867 he relocated to the Senckenberg Nature Research Society in Frankfurt as a geologist and mineralogist.
In 1873 he was appointed professor of geology at the University of Halle, followed by a full professorship the following year. At Halle, he occupied himself with paleobotanical research, and in the process amassed an impressive collection of fossil plants. He also conducted studies of coal deposits in the Saale valley, as well as scientific investigations of salt deposits west of Halle.
In 1877 he became a member of the German Academy of Sciences Leopoldina, becoming its president in 1895 as successor to Hermann Knoblauch (1820–1895).