Geoffrey Allan Boxshall FRS (born 13 June 1950^[1]) is a British zoologist, and Merit researcher at the Natural History Museum, working primarily on copepods.^[2]

Son of Jack Boxshall a Canadian bank manager and Sybil Boxshall (née Baker), a civil servant in the procurement department of the Ministry of Defence. He was educated at Churcher's College, Petersfield from 1961 to 1968.^[3] He was Vice Captain of College 1967–1968 and Captain of the Hockey XI 1968. He played rugby (open-side flanker) for Hampshire County in both the 1966–1967 and 1967–1968 seasons.

Boxshall is a whole organism biologist with a particular interest in copepod crustaceans. These are ubiquitous in aquatic systems but all radiated from a hyperbenthic origin in shallow marine waters. Multiple lineages of copepods colonised the open pelagic, fresh and subterranean waters, and colonised almost all other metazoan phyla as hosts as they adopted parasitism as a mode of life. The overarching aim of his research is to identify and understand the drivers generating the patterns of copepod biodiversity on the largest scales. His current focus is primarily on parasites: the repeated evolution of parasitism in copepods provides opportunities to examine the usage of different host taxa and to explore speciation patterns around major host colonisation or host switching events.^[4]

He earned a First Class BSc in Zoology in 1971, and PhD in 1974, from the University of Leeds.

In 1986 he was awarded the Scientific Medal of the Zoological Society of London for outstanding contributions to Zoology by a scientist under 40.^[5] In 1994 he became a Fellow of The Royal Society^[6] and in 1998, he was awarded the Crustacean Society's Award for Excellence in Research.^[7][8] In 2004 he received the Linnean Society medal for Zoology from the Linnean Society of London and in 2007 was elected as Honorary Vice-President of the Marine Biological Association of the United Kingdom.^[9] He delivered the 24th Annual Plymouth Marine Science Lecture in 2010^[10] on the topic "The magnitude of marine biodiversity: towards a quarter of a million species but not enough copepods!" In 2017 he was awarded the Achievement Award from the World Register of Marine Species (WoRMS).^[11]

In 1974 he joined the Natural History Museum's Department of Zoology as a Higher Scientific Officer, and progressed to Senior Scientific Officer (1976), Principal Scientific Officer (1980), Senior Principal Scientific Officer (1991), Deputy Chief Scientific Officer (Merit Researcher Band 2) (1997) and finally, to Merit Researcher Band 1 (2014) in the Department of Life Sciences.^[12] He retired in 2017.

Boxshall was the Secretary of the Zoological Society of London^[13] from 2011-2021 and was Vice-President of the Linnean Society Council from 2012–2013.^[14] He was a member of the Scientific Steering Committee of the World Register of Marine Species ^[15] (WoRMS) from 2009 to 2013 and he served as Chair of the committee from 2013 to 2016.

• Rony Huys, Geoffrey Allan Boxshall, Copepod evolution, Ray Society, 1991, ISBN 978-0-903874-21-2
• Geoffrey Allan Boxshall; Danielle Defaye, eds. (1993). Pathogens of wild and farmed fish: sea lice. CRC Press. ISBN 978-0-13-015504-7.
• C. D. Todd; M. S. Laverack; Geoffrey Allan Boxshall (1996). Coastal marine zooplankton: a practical manual for students. Cambridge University Press. ISBN 978-0-521-55533-3.
• Geoffrey Allan Boxshall, Sheila H. Halsey, An introduction to copepod diversity, Volume 2, Ray Society, 2004, ISBN 978-0-903874-31-1^[16]
• Lincoln, R.J., Boxshall, G.A. & Clark, P.F.  1998  Dictionary of Ecology, Evolution and Systematics.^[17]  Cambridge University Press, Cambridge. Revised and enlarged Second Edition. [1]ISBN 9780521438421
• Lincoln, R.J. & Boxshall, G.A.  1987  The Cambridge Illustrated Dictionary of Natural History.^[18] Cambridge University Press. ISBN 9780521399418

• Publications by Boxshall at World Register of Marine Species