Karl Otto Weber (29 December 1827 – 11 June 1867) was a German surgeon and pathologist born in Frankfurt am Main.

As a student at Bonn, he was a member of the Burschenschaft Franconia, which at that time also included Carl Schurz, Johannes Overbeck, Julius Schmidt, Friedrich Spielhagen, Ludwig Meyer and Adolf Strodtmann.

During the last part of his stay, he enjoyed a large degree of independence due to the failing eyesight of Wutzer.

Many of his medical articles were published in Pitha and Bilroth's Handbuch der allgemeinen und speciellen Chirurgie.

In the Preußischen Jahrbüchern he published the essays: “Johannes Müller,” “Alexander von Humboldt und sein Einfluß auf die Naturwissenschaft” (Alexander von Humboldt and his influence on natural science), an obituary for Karl Wilhelm Wutzer, and also “Ueber die Anfänge der pathologische Anatomie” (On the beginnings of pathological anatomy) and “Die Bedeutung der pathologische Anatomie für die medicinische Wissenschaft und Praxis” (The significance of pathological anatomy for the theory and practice of medicine).