Richard Ernst Wilhelm Otto (9 November 1872 – 12 August 1952) was a German physician and bacteriologist, who served as director of the Paul Ehrlich Institute until 1948.

He obtained his doctorate in medicine in 1895 and served as a military physician at the Prussian Institute of Infectious Diseases in Berlin from 1902.

He was appointed as a professor in 1906 and became a battalion physician and director of the bacteriological laboratory of the Army Medical Service in Hanover in 1907.

In the postwar era he was one of the editors of the textbook series Grenzgebiete der Medizin.

He retired from his office as director of the Paul Ehrlich Institute in August 1948.