John Fleming (10 January 1785 – 18 November 1857) was a Scottish Presbyterian clergyman, naturalist, zoologist and geologist. He was born near Bathgate in Linlithgowshire and died in Edinburgh. During his life he tried to reconcile theology with science.
After his studies at the University of Edinburgh in 1805, he became pastor the following year in the Church of Scotland and assigned the parish of Bressay in Scotland. He was ordained in 1808.
From 1808 in 1834, he served in various parishes in Scotland. In 1808, he participated in founding a learned society devoted to the natural history, the Wernerian Society.
John Fleming joined the Royal Society on 25 February 1813. In 1814, he becomes a doctor of theology at the University of St. Andrews. The same year he became a fellow of the Royal Society of Edinburgh.
In 1824 began the famous controversy between the geologist William Buckland (1784–1856) on the nature of The Flood as described in the Bible.
Fleming was a close associate of Robert Edmond Grant, who considered that the same laws of life affected all organisms. In 1828, Fleming published his History of British Animals. This book addressed not only current species, but also fossil species. It explains the presence of fossil climate change: the extinct species to survive here otherwise if weather conditions are favorable. These theories contributed to the advancement of biogeography. They exerted some influence on Charles Darwin (1809–1882).
In 1831, he found some fossils in the Old Red Sandstone units at Fife and recognized them as fossilized fish. This was something that didn't fit in the general accepted notion that the Earth was about 6,000 years old.
He was awarded the chair of natural philosophy at University and King's College in Aberdeen in 1834. In 1845, he became professor of natural history in New College, Edinburgh.