Franz Overbeck (1837, Saint Petersburg-1905, Basel), polyglot, historian and doctor of theology, was one of Nietzsche's best friends, along with Erwin Rohde, German philologist and Hellenist, and Paul Deussen, philosopher and Orientalist. He is recognized as a pioneer of liberal theological criticism.

In 1870, he was appointed professor at the University of Basel, a city in which he coincides with Nietzsche and where the foundations for a lasting and unconditional friendship began. In 1848 he was appointed rector of the University of Basel and he married Ida Rothpletz (1848 - 1933). Both cultivated the friendship with Nietzsche even after he lost his reason in Turin and the friend traveled to Italy to take care of the patient and protect his work. Overbeck made sure that the University of Basel granted him a life pension that he regularly sent to his mother, always worried about her financial problems.

Overbeck's staunch defense continued beyond the philosopher's death when his sister Elisabeth Förster-Nietzsche, director of the Nietzsche Archive, pressed for correspondence between him and his mother. Overbeck always opposed the Nazi interpretations that Nietzsche's sister wanted to attribute to his work, to the point of leaving the University of Basel as the depository of the correspondence that he maintained with Nietzsche's mother, upon her death, in 1905.