Edward Adelbert Doisy (November 13, 1893 – October 23, 1986)[1] was an American biochemist.

He received the Nobel Prize in Physiology or Medicine in 1943 with Henrik Dam for their discovery of vitamin K (K from "Koagulations-Vitamin" in German) and its chemical structure.

[1] In 1919 he accepted a faculty appointment in the Department of Biochemistry at Washington University in St. Louis, where he rose in rank to associate professor.

In 1923, he moved to Saint Louis University as professor and chairman of the new Department of Biochemistry.

They discovered the substance independently,[1] but only Butenandt was awarded the Nobel Prize in Chemistry in 1939.