Margaret Chorley Crosfield (1859–1952) was a British palaeontologist and geologist.
Crosfield initially studied at Newnham College, Cambridge in 1878, in which she started the study of Geology as part of her course, however she had to leave a year later due to ill health. She returned to the school 10 years later and gained special permission to study geology exclusively.
Crosfield became an active member of the Geologists' Association in 1892, later becoming a council member in 1918. In 1894 she was elected to the British Association for the Advancement of Science. She was one of the first six women to be elected Fellows of the Geological Society of London in 1919, the year that the law enforced the acceptance of women into such societies. She also was a member of the Palaeontological Society from 1907–1932. She collaborated with Gertrude Elles (1872–1960), Ethel Wood (1871–1945), and Ethel Skeat (1869–1939). Crosfield and Skeat investigated the Denbighshire grits and flags from 1906 to 1909 and in 1911, using graptolite to establish a sequence.
Crosfield kept meticulous ordered note books and field specimens, some of which are kept at the British Geological Survey in Keyworth, Nottingham. Interestingly the notebooks not only contain scientific data and observations but also give an insight into a life working "in the field". One such entry describes an encounter with a local rector in Wales, "Mr Watkins Williams is 89. A fine old man. He has just ordered a brick grave to be made for himself".
Crosfield was a promoter of women's suffrage and interestingly some of her field notes were written on the back of suffragette note paper. She was keen on education and sharing knowledge, giving many lectures and running field trips and well as attending many meetings both locally for Holmesdale Natural History Society and on a wider scale for the Geologist's Association.
- Burek, C. V.; Malpas, J. A. (2007). "Rediscovering and conserving the Lower Palaeozoic 'treasures' of Ethel Woods (neé Skeat) and Margaret Crosfield in northeast Wales". The Role of Women in the History of Geology. London: Geological Society. pp. 205–221. ISBN 1-86239-227-7.
- McConnell, Anita (2004). "Crosfield, Margaret Chorley (1859–1952)". Oxford Dictionary of National Biography. Oxford University Press. Retrieved 5 December 2013.