Cynthia Evelyn Longfield (16 August 1896 – 27 June 1991) was an Anglo-Irish entomologist and explorer and the first woman member of the Entomological Society.

She was the youngest daughter of Alice Elizabeth (née Mason) and Montifort Longfield, of Castle Mary, Cloyne, County Cork.

[6] Longfield joined the Army Service Corps during the First World War, later moving to an aircraft factory on Fullham Road.

[7] In the same year Longfield answered an advertisement to join Evelyn Cheesman of London Zoo on a research trip to the Pacific, specifically the Galapagos Islands.

[8] The pair used machetes to hack through the undergrowth of the Amazon jungle to collect specimens for the Natural History Museum in London.

On 28 March 1938 she joined the Auxiliary Fire Service, and during the Second World War ensured that a turntable ladder was used in response to the bombing of the biology department of the Natural History Museum in April 1941.

[8] In 1979 she donated dragonfly and damselfly specimens to the Royal Irish Academy, as well as her written records and more than 500 natural history books.

She died aged 96 on 27 June 1991 and was buried in St. Coleman's Church of Ireland Cathedral, close to her home in Cloyne.