Ludwig Otto Hölder (December 22, 1859 – August 29, 1937) was a German mathematician born in Stuttgart.

He first studied at the Polytechnikum (which today is the University of Stuttgart) and then in 1877 went to Berlin where he was a student of Leopold Kronecker, Karl Weierstrass, and Ernst Kummer.

The title of his doctoral thesis was "Beiträge zur Potentialtheorie" ("Contributions to potential theory").

[3] In 1933, Hölder signed the Vow of allegiance of the Professors of the German Universities and High-Schools to Adolf Hitler and the National Socialistic State.

[4] Holder's inequality, named for Hölder, was actually proven earlier by Leonard James Rogers.