Born in Penzance, Cornwall, he was the cousin of John William Colenso, Bishop of Natal. He trained as a printer's apprentice then travelled to New Zealand in 1834 to work for the Church Missionary Society as a printer/missionary. He was responsible for the printing of the Māori language translation of the New Testament. He was an avid botanist; detailing and transmitting to Kew Gardens in England previously unrecorded New Zealand flora. In 1866 he was the first New Zealander to be elected as a Fellow of the Royal Society. He wrote several books, and contributed over a hundred papers to scientific journals.
In the 1840s, from his mission station in Hawke's Bay, he made several long exploratory journeys through the central North Island in the company of Maori guides with the aim of reaching the inland Maori settlements of Patea, in the Taihape region, and converting them to Christianity. His travels took him through trackless forest, over the high Ruahine Range and across the Rangipo Desert and past the mountains of Ruapehu and Tongariro to the shores of Lake Taupo. In doing so he contributed greatly to the European exploration of the central North Island.
His standing in New Zealand colonial society and the Church Missionary Society, along with his fervent hope of ordination, was lost when it was discovered that he had sired a son (Wiremu) by Ripeka, the Māori maid of his wife, Elizabeth Fairburn Colenso.
|Parliament of New Zealand|
Following a long wilderness period during which he continued his botany work, he took an active role as a local politician in Napier. He represented Napier as the Member of Parliament for the Napier electorate from the 1861 by-election to 1866, when he retired.
He died in Napier in 1899, leaving two sons and a daughter. His son from Ripeka, Wiremu/William, left New Zealand for Cornwall, married a cousin and lived in Penzance until his death. His son from Elizabeth Fairburn, Ridley Latimer, attended Cambridge University, and finally settled in Scotland. His daughter Frances Mary married William Henry Simcox and settled in Otaki, New Zealand. Neither of his sons had surviving children – Frances had nine.
Published work 
- Colenso, William (1890). The Authentic and Genuine History of the Signing of the Treaty of Waitangi. Wellington: By Authority of George Didsbury, Government Printer. Retrieved 16 Sept. 2011.
Colenso Society 
Founded in 2010 by academics and historians across New Zealand, the Colenso Society aims to to promote the study of the life and work of the Reverend William Colenso FLS FRS.
- William Colenso: Printer, Missionary, Botanist, Explorer, Politician by A. G. Bagnall & G. C. Petersen (1948, AH & AW Reed, Wellington)
- The Controversial Colensos by A. L. Rowse (1989, Cornish Publications, Redruth, Cornwall) ISBN 1-85022-047-6 (Bishop Colenso of Natal and his cousin William Colenso, naturalist)
- New Zealand Explorers by Philip Temple (1985, Whitcoulls Publishers, Christchurch, NZ)
- Biography in 1966 An Encyclopaedia of New Zealand
- William Colenso biography from the Dictionary of New Zealand Biography
- 1899, Appreciation in Transactions of the Royal Society of New Zealand
- Archival material relating to William Colenso listed at the UK National Archives
- Entry in The Cyclopedia of New Zealand, 1908
- Biography in Botanical Discovery in New Zealand: The Resident Botanists by W. R. B. Oliver
- William Colenso in Signposts - a blog about Te Ara
- The Colenso Project / The Colenso Society
|New Zealand Parliament|
Henry Powning Stark
|Member of Parliament for Napier