Jacob Katzenstein (January 7, 1864 – September 3, 1921) was a German otorhinolaryngologist born in Preußisch Oldendorf.
He studied medicine in Berlin and Freiburg im Breisgau, earning his doctorate in 1888. Afterwards he worked as assistant to otorhinolaryngologist Benno Baginsky (1848–1919) in Berlin. From 1909 he was a lecturer at the University of Berlin.
Katzenstein specialized in research of voice disorders and is known for physiological investigations of the larynx. In 1913 he became editor of the "Archiv für experimentelle und klinische Phonetik" (Archive for experimental and clinical phonetics).