Moseley was born in Wandsworth, London, the son of the Canon Henry Moseley FRS (himself Professor of Natural Philosophy and Astronomy at King's College London, Schools Inspector, Canon of Bristol and Chaplain in Ordinary to the Queen). He was educated at Harrow, Oxford (Arts), and at the University of London (medicine). He married Amabel Gwyn Jeffreys, daughter of the conchologist J. Gwyn Jeffries, FRS in 1881, and they were the parents of the noted British physicist Henry Gwyn Jeffreys Moseley.
Moseley delivered the Royal Society Croonian Lecture in 1878 and was elected as a Fellow of the Royal Society in 1879.He participated as naturalist in expeditions to Ceylon, to California, and to Oregon, and most notably he was in the HMS Challenger expedition of 1872 through 1876 which covered over 120,000 km. of the world's oceans. Moseley began working at the University of London in 1879, and he was awarded the Linacre chair of human and comparative anatomy at the University of Oxford in 1881. In the same year, Moseley became involved in the negotiations for the donation of the Pitt-Rivers donation, which would form the Pitt Rivers Museum from 1884. Moseley, with Edward Burnett Tylor, oversaw the transfer of Pitt-Rivers' collection from London to Oxford
Moseley exerted significant influences on his noted students Halford Mackinder and Walter Garstang, who changed his career choice from medicine to zoology under Moseley's supervision. Moseley was awarded the Royal Society's Royal Medal in 1887.
Moseley's publications include :
- On Oregon (1878).
- On the Structure of the Sylasteridae (1878).
- Notes by a Naturalist on the Challenger (1879).
Moseley is commemorated in the Latin name of the species, Northern Rockhopper Penguin, the Eudyptes moseleyi.
- Allen G. Debus (ed.) (1968). World Who’s Who in Science. A Biographical Dictionary of Notable Scientists from Antiquity to the Present. Marquis-Who’s Who (Chicago) : xvi + 1855 p.
- Sir Halford Mackinder, 1861 - 1947: Some New Perspectives, by Brian Blouet, Research Paper 13, School of Geography, University of Oxford 1975
- "Author Query for 'H.Moseley'". International Plant Names Index.