Franz Rühl (26 October 1845, Hanau – 3 July 1915, Jena) was a German historian who published numerous works in the field of classical history. He was a son-in-law to anatomist Jacob Henle.
He studied history and philology at the universities of Jena and Marburg, receiving his doctorate in 1867. After graduation, he took a study trip to Italy and worked as a gymnasium teacher in Schleswig. In 1871 he obtained his habilitation at the University of Leipzig, and during the following year relocated to Dorpat, where he subsequently became an associate professor of history. From 1876 onward, he was a professor at the University of Königsberg, serving as university rector in 1905/06.
From 1872 up until his death, he published numerous articles in the scientific journal Rheinisches Museum für Philologie. He was the editor of Alfred von Gutschmid's Kleine Schriften (5 volumes, 1889-1904), and after the death of Wilhelm Adolf Schmidt, he published Schmidt's Handbuch der griechischen chronologie ("Handbook of Greek chronology", 1888). Rühl's other noted works are as follows: