William Culp Darrah

William Culp Darrah (1909, Reading, Pennsylvania – 1989, Gettysburg, Pennsylvania) was an American professor of biology at Gettysburg College in Pennsylvania. He was a specialist in paleobotany. He was also a noted authority on the history of photography, writing several books about 19th-century photo processes and photographers. As part of his interest in 19th-century photography, he assembled a collection of over 60,000 cartes-de-visite, which is now held at Penn State University.

Darrah was a fellow of the American Association for the Advancement of Science, as well a member of Sigma Xi and the Botanical Society of America.