Ernst Wilhelm Theodor Trendelenburg (16 July 1877 – 16 March 1946) was a German physiologist known for his work in physiological optics.
He worked as an assistant to Johannes von Kries at Freiburg and to Ewald Hering at Leipzig.
In 1904 he obtained his habilitation for physiology at Freiburg, and in 1911 became a full professor at the University of Innsbruck.
[5] During his time spent at the University of Freiburg he conducted studies involving animal psychology that included intelligence testing with monkeys.
[6] He was also co-editor of the periodical Zeitschrift für die gesamte experimentelle Medizin.