Sir Peter Chalmers Mitchell CBE FRS FZS (23 November 1864 – 2 July 1945) was a Scottish zoologist who was Secretary of the Zoological Society of London from 1903 to 1935.

Mitchell gained an MA at the University of Aberdeen, and moved to Christ Church, Oxford, where he read for natural science, specialising in zoology.

[4] In 1896, he was the anonymous author of an article in the Saturday Review entitled "A Biological View of English Foreign Policy"[5] which proposed the inevitability of a final battle between Britain and Germany, in which one would have to be destroyed.

[citation needed] In April 1916, now an army Captain, he was responsible for setting up a specialist department MI7(B)4 to oversee the production of military propaganda to be dropped from the air over enemy lines.

[7] On retiring from the zoo, Mitchell moved to Málaga, staying there during the first six months or so of the Spanish Civil War, until the city was taken on behalf of the rebels by Italian troops.

In addition, like Henry Scherren FZS, Chalmers Mitchell made a number of contributions to the 1911 Encyclopædia Britannica under the initials "P.C.M.".