Alfred Richard Cecil Selwyn was born on July 28, 1824, in Kilmington, England.

He was a geologist and civil servant. Educated at home by private tutors and later in Switzerland, he became interested in geology by collecting fossils as a hobby. In 1845, he joined the Geological Survey of Great Britain as an assistant geologist and was promoted to the geologist in 1848. In 1852, the Colonial Office appointed Selwyn as geological surveyor to the newly founded Australian colony of Victoria and later made him its director. During his 17 years as director, over 60 geological maps and numerous reports were issued. He also served other public functions in Victoria as a member of the Mining Commission, the Board of Science, the Board of Agriculture, and commissions for the exhibitions at Victoria (1861), London (1862), Dublin (1865), and Paris (1866). After the government funding to survey was discontinued in 1869, Selwyn accepted an offer to become director of the Geological Survey of Canada (GSC). His 25 years as director was a period of intense activity during which GSC geologists mounted expeditions to many parts of the newly added territories. Selwyn inspected the Eastern Townships of Quebec, New Brunswick, and Nova Scotia. As an accomplished mountain climber, he participated in an arduous expedition to investigate the geology and mineral resources along the proposed railroad routes in British Columbia. He was a Fellow of the Royal Geographical Society (1871) and of the Royal Society (1874), was created the Companion of Order of St. Michael and St. George in 1886 and was a foreign member of scientific societies in 14 countries. He also served as President of the Royal Society of Canada (1895-1896). He received the Murchison Medal of the Geological Society in 1876 and the Clarke Medal by the Royal Society of New South Wales in 1884. In Melbourne, he was on the councils of the Philosophical Society (1855) and the Philosophical Institute (1857); he was also a councillor of the Acclimatisation Society. In 1894, he retired to Vancouver, British Columbia.

In 1852, he married Matilda Charlotte Selwyn (1833–1882). He died on October 18, 1902, in Vancouver, British Columbia.