William Henry Parr Greswell, English clergyman and author, was the son of Reverend William Parr Greswell and his wife Mary Ann, born Harrison. He was educated at Somersetshire College, Bath, and Brasenose College, Oxford, where he was awarded the degrees Bachelor of Arts (BA, 1871) and Master of Arts (MA, 1873). From 1876 to 1884 he was a lecturer of classics and English literature under the Higher Education Act of the Cape Colony. In 1878 was admitted to the MA degree by the University of the Cape of Good Hope on the basis of his degrees from Oxford. From 1888 to 1913 he was Rector of Dodington, Somerset. He was a Fellow of the Royal Geographical Society and was elected a Fellow of the Royal Colonial Society in March 1882. In 1895 he married Blanche Caroline Annie Carew.
Greswell wrote several books relating to South Africa and the British colonies in general. Of most scientific interest was A geography of Africa south of the Zambesi; with notes on the industries, wealth, and social progress of the states and peoples (with 3 maps), published under the auspices of the Royal Colonial Institute (Oxford, 1892). Others were Our South African empire (London, 1885, 2 vols), The British colonies and their industries (1893), Outlines of British colonisation (London, 1893), and The growth and administration of the British colonies, 1837-1897... (1898). Other books by him were Geography of the dominion of Canada and Newfoundland (Oxford, 1891) and The United States and their industries (London, 1899). He also contributed many articles on a variety of topics to Victorian magazines, including "Village life in South Africa" (1885), "Wilds and woodlands of the Cape" (1886), "Sea fishing at the Cape" (1890), "Federation in South Africa" (1897), and "Aspects of the Boer War" (1900). After about 1902 he showed little or no interest in southern Africa and wrote mainly on the history of Somerset.
Greswell practised ornithology as a recreational activity. A short paper by him on "The sea birds of the Cape", illustrated by Charles Whymper, was published in Good Words (1895) and also became available as a pamphlet.