Karl Praechter (17 October 1858, Heidelberg – 18 February 1933, Halle an der Saale) was a German classical philologist.
From 1877 he studied theology in Lausanne, followed by studies of classical philology at several German universities.
He worked as a gymnasium teacher in the municipalities of Durlach and Bruchsal, and in 1889 obtained his habilitation in classical philology from the University of Bern.
In 1899 he became a full professor at Bern, and later relocated to the University of Halle, where from 1907 to 1926, he served as a professor of classical philology.