Sir Guy Anstruther Knox Marshall FRS (20 December 1871 in Amritsar, Punjab – 8 April 1959 in London), was an Indian-born British entomologist.
Both Guy's father and his uncle, Major-General George Frederick Leycester Marshall (1843–1934), were naturalists who had produced books on the birds and butterflies of India, Burma, and Ceylon.
When he failed the Indian Civil Service entrance examination, his father shipped him off to Natal in South Africa to learn sheep farming.
Marshall corresponded with the prominent Darwinian, Edward Bagnall Poulton, Hope Professor of Zoology at Oxford University who had written The Colours of Animals (1890).
The committee's function was to post field entomologists to East and West Africa who would study insects harmful to humans, crops and animals and send specimens to the Natural History Museum in London for identification.