Friedrich Leo (July 10, 1851 – January 15, 1914) was a German classical philologist born in Regenwalde, in the then-province of Pomerania (present-day Resko, Poland).
From 1868 he was a student at the University of Göttingen, and following military duty in the Franco-Prussian War, he continued his education at the University of Bonn, where he had as instructors Franz Bücheler and Hermann Usener.
At the latter institution he was university rector (1903–4), and was a colleague of Ulrich von Wilamowitz-Moellendorff.
Much of Leo's earlier work concerned research of Seneca's tragedies and the writings of Venantius Fortunatus.
Both Leo and his wife came from families who were assimilated German Jews, having converted to Lutheranism in the early 19th century.