Erasmus Darwin Barlow, FRCPsych, FZS (15 April 1915 – 2 August 2005) was a British psychiatrist, physiologist and businessman. Born in London in 1915, he was the second son of Sir Alan Barlow, son of Sir Thomas Barlow, royal physician. His mother was Lady Nora Barlow, daughter of Sir Horace Darwin. He was a great-grandson of the naturalist Charles Darwin. Although Erasmus has been a common name in the family since the time of his great-great-great-grandfather Erasmus Darwin (and, in turn, since his ancestor Erasmus Earle), he was named after his mother's brother, his uncle Erasmus Darwin IV who was killed at the Second Battle of Ypres on 24 April, nine days after he was born. His elder brother was Commodore Sir Thomas Erasmus Barlow, a younger brother is Horace Barlow.